diff --git a/AOC.Common/Day.cs b/AOC.Common/Day.cs
index e9a7787..d61b869 100644
--- a/AOC.Common/Day.cs
+++ b/AOC.Common/Day.cs
@@ -22,16 +22,25 @@ public abstract class Day
         Path.Combine(AppDomain.CurrentDomain.BaseDirectory,
             $"input{Year}/{(UseTestInput ? "test" : "day")}{DayNumber,2:00}.in");
 
+    public abstract void ProcessInput();
+
     public abstract object Part1();
     public abstract object Part2();
 
     private void AllParts(bool verbose = true)
     {
-        Console.WriteLine($"{Year} Day {DayNumber,2}: {PuzzleName}");
+        Console.Write($"{Year} Day {DayNumber,2}: {PuzzleName,-31}");
+        
         var s = Stopwatch.StartNew();
+        ProcessInput();
+        s.Stop();
+        Console.WriteLine($"{s.ScaleMilliseconds()}ms elapsed processing input");
+        s.Reset();
+        
+        s.Start();
         var part1 = Part1();
         s.Stop();
-        Console.Write($"Part 1: {part1,-25} ");
+        Console.Write($"Part 1: {part1,-35} ");
         Console.WriteLine(verbose ? $"{s.ScaleMilliseconds()}ms elapsed" : "");
 
         s.Reset();
@@ -39,7 +48,7 @@ public abstract class Day
         s.Start();
         var part2 = Part2();
         s.Stop();
-        Console.Write($"Part 2: {part2,-25} ");
+        Console.Write($"Part 2: {part2,-35} ");
         Console.WriteLine(verbose ? $"{s.ScaleMilliseconds()}ms elapsed" : "");
 
         Console.WriteLine();
diff --git a/AOC.Test/Common.cs b/AOC.Test/Common.cs
index ab60ee6..2176332 100644
--- a/AOC.Test/Common.cs
+++ b/AOC.Test/Common.cs
@@ -5,13 +5,15 @@ public static class Common
     public static void CheckDay(Type dayType, string part1, string part2, bool testInput = false)
     {
         Day.UseTestInput = testInput;
-        var s = Stopwatch.StartNew();
         var day = Activator.CreateInstance(dayType) as Day;
-        s.Stop();
         Assert.IsNotNull(day, "failed to instantiate day object");
         Assert.IsTrue(File.Exists(day.FileName), $"File.Exists(day.FileName) {day.FileName}");
         Console.Write($"{day.Year} Day {day.DayNumber,2}: {day.PuzzleName,-25} ");
-        Console.WriteLine($"{s.ScaleMilliseconds()} ms elapsed in constructor");
+        
+        var s = Stopwatch.StartNew();
+        day.ProcessInput();
+        s.Stop();
+        Console.WriteLine($"{s.ScaleMilliseconds()} ms elapsed processing input");
 
         // part 1
         s.Reset();
diff --git a/AOC2015/Day01.cs b/AOC2015/Day01.cs
index 8c27f11..17db815 100644
--- a/AOC2015/Day01.cs
+++ b/AOC2015/Day01.cs
@@ -6,6 +6,10 @@ public class Day01 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         var floor = 0;
diff --git a/AOC2015/Day02.cs b/AOC2015/Day02.cs
index d6e2bd7..0c154f9 100644
--- a/AOC2015/Day02.cs
+++ b/AOC2015/Day02.cs
@@ -5,16 +5,20 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day02 : Day
 {
-    private readonly List<List<int>> _gifts;
+    private List<List<int>>? _gifts;
     
     public Day02() : base(2015, 2, "I Was Told There Would Be No Math")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _gifts = Input.Select(line => line.Split('x').Select(int.Parse).ToList()).ToList();
     }
 
     public override object Part1()
     {
-        return _gifts.Sum(gift =>
+        return _gifts!.Sum(gift =>
         {
             var biggestDimension = gift.IndexOf(gift.Max());
 
@@ -33,7 +37,7 @@ public sealed class Day02 : Day
 
     public override object Part2()
     {
-        return _gifts.Sum(gift =>
+        return _gifts!.Sum(gift =>
         {
             var biggestDimension = gift.IndexOf(gift.Max());
             var bowArea = gift.Aggregate(1, (i, i1) => i * i1);
diff --git a/AOC2015/Day03.cs b/AOC2015/Day03.cs
index bb1fe27..4209db9 100644
--- a/AOC2015/Day03.cs
+++ b/AOC2015/Day03.cs
@@ -9,6 +9,10 @@ public sealed class Day03 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         int x = 0, y = 0;
diff --git a/AOC2015/Day04.cs b/AOC2015/Day04.cs
index 0b41ae4..57fcc12 100644
--- a/AOC2015/Day04.cs
+++ b/AOC2015/Day04.cs
@@ -7,22 +7,25 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day04 : Day
 {
-    private readonly string _key;
+    private string? _key;
 
     public Day04() : base(2015, 4, "The Ideal Stocking Stuffer")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _key = Input.First();
     }
 
     public override object Part1()
     {
-        var md5 = MD5.Create();
         var counter = 0;
 
         while (true)
         {
-            var hash = md5.ComputeHash(Encoding.ASCII.GetBytes(_key + counter));
-            if (BitConverter.ToString(hash).Replace("-", "").StartsWith("00000")) 
+            var hash = MD5.HashData(Encoding.ASCII.GetBytes(_key + counter));
+            if (BitConverter.ToString(hash).Replace("-", "").StartsWith("00000"))
                 return counter;
             counter++;
         }
@@ -30,12 +33,11 @@ public sealed class Day04 : Day
 
     public override object Part2()
     {
-        var md5 = MD5.Create();
         var counter = 0;
 
         while (true)
         {
-            var hash = md5.ComputeHash(Encoding.ASCII.GetBytes(_key + counter));
+            var hash = MD5.HashData(Encoding.ASCII.GetBytes(_key + counter));
             if (BitConverter.ToString(hash).Replace("-", "").StartsWith("000000"))
                 return counter;
             counter++;
diff --git a/AOC2015/Day05.cs b/AOC2015/Day05.cs
index d1f747f..7cd0ffa 100644
--- a/AOC2015/Day05.cs
+++ b/AOC2015/Day05.cs
@@ -5,9 +5,13 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day05 : Day
 {
-    private readonly List<string> _strings;
     private static readonly List<char> Vowels = new() { 'a', 'e', 'i', 'o', 'u' };
-    
+    private List<string> _strings = new();
+
+    public Day05() : base(2015, 5, "Doesn't He Have Intern-Elves For This?")
+    {
+    }
+
     [GeneratedRegex(@"(.)\1")]
     private static partial Regex DoubleLetter();
 
@@ -17,7 +21,7 @@ public sealed partial class Day05 : Day
     [GeneratedRegex(@"(..).*\1")]
     private static partial Regex TwoPairs();
 
-    public Day05() : base(2015, 5, "Doesn't He Have Intern-Elves For This?")
+    public override void ProcessInput()
     {
         _strings = Input.Where(line => !string.IsNullOrEmpty(line)).ToList();
     }
diff --git a/AOC2015/Day06.cs b/AOC2015/Day06.cs
index 73a4944..4dc3677 100644
--- a/AOC2015/Day06.cs
+++ b/AOC2015/Day06.cs
@@ -5,13 +5,17 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day06 : Day
 {
+    private readonly Dictionary<(int x, int y), int> _brightnessGrid = new();
+    private readonly Dictionary<(int x, int y), bool> _lightGrid = new();
+
+    public Day06() : base(2015, 6, "Probably a Fire Hazard")
+    {
+    }
+
     [GeneratedRegex(@"(\d+),(\d+) through (\d+),(\d+)")]
     private static partial Regex Coords();
 
-    private readonly Dictionary<(int x, int y), bool> _lightGrid = new();
-    private readonly Dictionary<(int x, int y), int> _brightnessGrid = new();
-
-    public Day06() : base(2015, 6, "Probably a Fire Hazard")
+    public override void ProcessInput()
     {
     }
 
diff --git a/AOC2015/Day07.cs b/AOC2015/Day07.cs
index ee5ec2c..7de459e 100644
--- a/AOC2015/Day07.cs
+++ b/AOC2015/Day07.cs
@@ -5,13 +5,17 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day07 : Day
 {
-    private readonly Dictionary<string, ushort> _wires = new();
     private readonly Dictionary<string, Func<ushort>> _actions = new();
+    private readonly Dictionary<string, ushort> _wires = new();
 
     public Day07() : base(2015, 7, "Some Assembly Required")
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         ProcessInstructions();
diff --git a/AOC2015/Day08.cs b/AOC2015/Day08.cs
index bcf099e..ff7c7db 100644
--- a/AOC2015/Day08.cs
+++ b/AOC2015/Day08.cs
@@ -5,10 +5,14 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day08 : Day
 {
+    public Day08() : base(2015, 8, "Matchsticks")
+    {
+    }
+
     [GeneratedRegex(@"^""(\\x..|\\.|.)*""$")]
     private static partial Regex CharSet();
 
-    public Day08() : base(2015, 8, "Matchsticks")
+    public override void ProcessInput()
     {
     }
 
diff --git a/AOC2015/Day09.cs b/AOC2015/Day09.cs
index 2aa2795..be9696b 100644
--- a/AOC2015/Day09.cs
+++ b/AOC2015/Day09.cs
@@ -5,11 +5,14 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day09 : Day
 {
-    private record Distance(string Start, string End, int Length);
     private readonly List<Distance> _distances = new();
-    private readonly int _shortest = int.MaxValue, _longest;
+    private int _shortest = int.MaxValue, _longest;
 
     public Day09() : base(2015, 9, "All in a Single Night")
+    {
+    }
+
+    public override void ProcessInput()
     {
         foreach (var split in Input.Select(line => line.Split(' ')))
         {
@@ -34,4 +37,6 @@ public sealed class Day09 : Day
     public override object Part1() => _shortest;
 
     public override object Part2() => _longest;
+
+    private record Distance(string Start, string End, int Length);
 }
diff --git a/AOC2015/Day10.cs b/AOC2015/Day10.cs
index 5fd54c8..f2b4456 100644
--- a/AOC2015/Day10.cs
+++ b/AOC2015/Day10.cs
@@ -8,6 +8,10 @@ public sealed class Day10 : Day
     private string _seed;
 
     public Day10() : base(2015, 10, "Elves Look, Elves Say")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _seed = Input.First();
     }
@@ -50,4 +54,4 @@ public sealed class Day10 : Day
         yield return count;
         yield return currentDigit - '0';
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2015/Day11.cs b/AOC2015/Day11.cs
index 2afbd51..7784102 100644
--- a/AOC2015/Day11.cs
+++ b/AOC2015/Day11.cs
@@ -5,23 +5,27 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day11 : Day
 {
-    private char[] _password;
+    private char[]? _password;
 
     public Day11() : base(2015, 11, "Corporate Policy")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _password = Input.First().ToCharArray();
     }
 
     public override object Part1()
     {
-        while (!IsValid(ref _password)) Increment(ref _password);
+        while (!IsValid(ref _password!)) Increment(ref _password);
 
         return new string(_password);
     }
 
     public override object Part2()
     {
-        Increment(ref _password);
+        Increment(ref _password!);
         while (!IsValid(ref _password)) Increment(ref _password);
 
         return new string(_password);
diff --git a/AOC2015/Day12.cs b/AOC2015/Day12.cs
index a4061fa..d61e1a8 100644
--- a/AOC2015/Day12.cs
+++ b/AOC2015/Day12.cs
@@ -15,6 +15,10 @@ public sealed partial class Day12 : Day
     [GeneratedRegex(@"-?\d+")]
     private static partial Regex Digits();
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1() =>
         Digits().Matches(Input.First()).Sum(n => int.Parse(n.Value));
 
diff --git a/AOC2015/Day13.cs b/AOC2015/Day13.cs
index 0341397..a5f7df1 100644
--- a/AOC2015/Day13.cs
+++ b/AOC2015/Day13.cs
@@ -11,6 +11,10 @@ public sealed class Day13 : Day
     private readonly List<string> _people = new();
 
     public Day13() : base(2015, 13, "Knights of the Dinner Table")
+    {
+    }
+
+    public override void ProcessInput()
     {
         foreach (var line in Input)
             AddToHappinessMap(line);
diff --git a/AOC2015/Day14.cs b/AOC2015/Day14.cs
index 83f8056..8cca5a8 100644
--- a/AOC2015/Day14.cs
+++ b/AOC2015/Day14.cs
@@ -5,19 +5,23 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day14 : Day
 {
-    private readonly List<Reindeer> _reindeer;
+    private List<Reindeer>? _reindeer;
 
     public Day14() : base(2015, 14, "Reindeer Olympics")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _reindeer = Input.Select(i => new Reindeer(i)).ToList();
     }
 
     public override object Part1() =>
-        _reindeer.Select(r => r.Fly(2503)).Max();
+        _reindeer!.Select(r => r.Fly(2503)).Max();
 
     public override object Part2() =>
         Enumerable.Range(1, 2503)
-            .SelectMany(time => _reindeer.GroupBy(r => r.Fly(time)).OrderByDescending(r => r.Key).First())
+            .SelectMany(time => _reindeer!.GroupBy(r => r.Fly(time)).OrderByDescending(r => r.Key).First())
             .GroupBy(r => r)
             .Max(g => g.Count());
 
diff --git a/AOC2015/Day15.cs b/AOC2015/Day15.cs
index 0608c30..4b7fad8 100644
--- a/AOC2015/Day15.cs
+++ b/AOC2015/Day15.cs
@@ -5,25 +5,33 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day15 : Day
 {
-    [GeneratedRegex(@"-?\d+")]
-    private static partial Regex Digits();
-
-    private record Ingredient(string Name, int Capacity, int Durability, int Flavor, int Texture, int Calories);
-
-    private readonly List<Ingredient> _ingredients;
-    private readonly int _best;
-    private readonly int _best500Cals;
+    private int _best;
+    private int _best500Cals;
 
     public Day15() : base(2015, 15, "Science for Hungry People")
     {
-        _ingredients = Input.Select(ParseIngredient).ToList();
+    }
 
-        var quantities = new int[_ingredients.Count];
+    [GeneratedRegex(@"-?\d+")]
+    private static partial Regex Digits();
+
+    private static Ingredient ParseIngredient(string line)
+    {
+        var s = line.Split(':');
+        var nums = Digits().Matches(s[1]).Select(match => int.Parse(match.Value)).ToList();
+
+        return new(s[0], nums[0], nums[1], nums[2], nums[3], nums[4]);
+    }
+
+    public override void ProcessInput()
+    {
+        var ingredients = Input.Select(ParseIngredient).ToList();
+        var quantities = new int[ingredients.Count];
         _best = 0;
 
         while (true)
         {
-            for (var i = 0; i < _ingredients.Count; i++)
+            for (var i = 0; i < ingredients.Count; i++)
             {
                 quantities[i]++;
                 if (quantities[i] > 100)
@@ -31,17 +39,17 @@ public sealed partial class Day15 : Day
                 else break;
             }
 
-            var quantityApplied = quantities.Take(_ingredients.Count - 1).Sum();
+            var quantityApplied = quantities.Take(ingredients.Count - 1).Sum();
             if (quantityApplied == 0) break;
             if (quantityApplied > 100) continue;
 
             quantities[^1] = 100 - quantityApplied;
 
             int cap = 0, dur = 0, fla = 0, tex = 0, cal = 0;
-            for (var j = 0; j < _ingredients.Count; j++)
+            for (var j = 0; j < ingredients.Count; j++)
             {
                 var q = quantities[j];
-                var i = _ingredients[j];
+                var i = ingredients[j];
 
                 cap += q * i.Capacity;
                 dur += q * i.Durability;
@@ -57,15 +65,9 @@ public sealed partial class Day15 : Day
         }
     }
 
-    private static Ingredient ParseIngredient(string line)
-    {
-        var s = line.Split(':');
-        var nums = Digits().Matches(s[1]).Select(match => int.Parse(match.Value)).ToList();
-
-        return new(s[0], nums[0], nums[1], nums[2], nums[3], nums[4]);
-    }
-
     public override object Part1() => _best;
 
     public override object Part2() => _best500Cals;
+
+    private record Ingredient(string Name, int Capacity, int Durability, int Flavor, int Texture, int Calories);
 }
diff --git a/AOC2015/Day16.cs b/AOC2015/Day16.cs
index 1008c15..2e54214 100644
--- a/AOC2015/Day16.cs
+++ b/AOC2015/Day16.cs
@@ -9,6 +9,10 @@ public sealed class Day16 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1() => "";
 
     public override object Part2() => "";
diff --git a/AOC2015/Day17.cs b/AOC2015/Day17.cs
index c2a7fd7..54df631 100644
--- a/AOC2015/Day17.cs
+++ b/AOC2015/Day17.cs
@@ -8,6 +8,10 @@ public sealed class Day17 : Day
     public Day17() : base(2015, 17, "No Such Thing as Too Much")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day18.cs b/AOC2015/Day18.cs
index 693e454..e8af781 100644
--- a/AOC2015/Day18.cs
+++ b/AOC2015/Day18.cs
@@ -8,6 +8,10 @@ public sealed class Day18 : Day
     public Day18() : base(2015, 18, "Like a GIF For Your Yard")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day19.cs b/AOC2015/Day19.cs
index 54494ed..d600c3f 100644
--- a/AOC2015/Day19.cs
+++ b/AOC2015/Day19.cs
@@ -8,6 +8,10 @@ public sealed class Day19 : Day
     public Day19() : base(2015, 19, "Medicine for Rudolph")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day20.cs b/AOC2015/Day20.cs
index cfd4d75..29ba85b 100644
--- a/AOC2015/Day20.cs
+++ b/AOC2015/Day20.cs
@@ -8,6 +8,10 @@ public sealed class Day20 : Day
     public Day20() : base(2015, 20, "Infinite Elves and Infinite Houses")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day21.cs b/AOC2015/Day21.cs
index fbda0b4..17f44c1 100644
--- a/AOC2015/Day21.cs
+++ b/AOC2015/Day21.cs
@@ -8,6 +8,10 @@ public sealed class Day21 : Day
     public Day21() : base(2015, 21, "RPG Simulator 20XX")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day22.cs b/AOC2015/Day22.cs
index 6df2327..0edc206 100644
--- a/AOC2015/Day22.cs
+++ b/AOC2015/Day22.cs
@@ -8,6 +8,10 @@ public sealed class Day22 : Day
     public Day22() : base(2015, 22, "Wizard Simulator 20XX")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day23.cs b/AOC2015/Day23.cs
index 4d5e343..f30d1c9 100644
--- a/AOC2015/Day23.cs
+++ b/AOC2015/Day23.cs
@@ -8,6 +8,10 @@ public sealed class Day23 : Day
     public Day23() : base(2015, 23, "Opening the Turing Lock")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day24.cs b/AOC2015/Day24.cs
index 416202c..0c6c8ad 100644
--- a/AOC2015/Day24.cs
+++ b/AOC2015/Day24.cs
@@ -8,6 +8,10 @@ public sealed class Day24 : Day
     public Day24() : base(2015, 24, "It Hangs in the Balance")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2015/Day25.cs b/AOC2015/Day25.cs
index 9610669..6a6f778 100644
--- a/AOC2015/Day25.cs
+++ b/AOC2015/Day25.cs
@@ -8,6 +8,10 @@ public sealed class Day25 : Day
     public Day25() : base(2015, 25, "Let It Snow")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day01.cs b/AOC2016/Day01.cs
index 13dddeb..5207ba8 100644
--- a/AOC2016/Day01.cs
+++ b/AOC2016/Day01.cs
@@ -8,6 +8,10 @@ public sealed class Day01 : Day
     public Day01() : base(2016, 1, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day02.cs b/AOC2016/Day02.cs
index f301c74..be784c8 100644
--- a/AOC2016/Day02.cs
+++ b/AOC2016/Day02.cs
@@ -8,6 +8,10 @@ public sealed class Day02 : Day
     public Day02() : base(2016, 2, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day03.cs b/AOC2016/Day03.cs
index 1dcb284..fd6a537 100644
--- a/AOC2016/Day03.cs
+++ b/AOC2016/Day03.cs
@@ -8,6 +8,10 @@ public sealed class Day03 : Day
     public Day03() : base(2016, 3, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day04.cs b/AOC2016/Day04.cs
index 040e431..2585cc2 100644
--- a/AOC2016/Day04.cs
+++ b/AOC2016/Day04.cs
@@ -8,6 +8,10 @@ public sealed class Day04 : Day
     public Day04() : base(2016, 4, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day05.cs b/AOC2016/Day05.cs
index 4a811eb..216776a 100644
--- a/AOC2016/Day05.cs
+++ b/AOC2016/Day05.cs
@@ -8,6 +8,10 @@ public sealed class Day05 : Day
     public Day05() : base(2016, 5, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day06.cs b/AOC2016/Day06.cs
index ecd7d3f..24c08b9 100644
--- a/AOC2016/Day06.cs
+++ b/AOC2016/Day06.cs
@@ -8,6 +8,10 @@ public sealed class Day06 : Day
     public Day06() : base(2016, 6, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day07.cs b/AOC2016/Day07.cs
index 67886e3..115d8e8 100644
--- a/AOC2016/Day07.cs
+++ b/AOC2016/Day07.cs
@@ -8,6 +8,10 @@ public sealed class Day07 : Day
     public Day07() : base(2016, 7, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day08.cs b/AOC2016/Day08.cs
index acf66ee..3e83364 100644
--- a/AOC2016/Day08.cs
+++ b/AOC2016/Day08.cs
@@ -8,6 +8,10 @@ public sealed class Day08 : Day
     public Day08() : base(2016, 8, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day09.cs b/AOC2016/Day09.cs
index 009493d..f4f471e 100644
--- a/AOC2016/Day09.cs
+++ b/AOC2016/Day09.cs
@@ -8,6 +8,10 @@ public sealed class Day09 : Day
     public Day09() : base(2016, 9, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day10.cs b/AOC2016/Day10.cs
index cb7c29c..3cb11e6 100644
--- a/AOC2016/Day10.cs
+++ b/AOC2016/Day10.cs
@@ -8,6 +8,10 @@ public sealed class Day10 : Day
     public Day10() : base(2016, 10, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day11.cs b/AOC2016/Day11.cs
index c07f54b..08aa3a8 100644
--- a/AOC2016/Day11.cs
+++ b/AOC2016/Day11.cs
@@ -8,6 +8,10 @@ public sealed class Day11 : Day
     public Day11() : base(2016, 11, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day12.cs b/AOC2016/Day12.cs
index c052ef8..d32f626 100644
--- a/AOC2016/Day12.cs
+++ b/AOC2016/Day12.cs
@@ -8,6 +8,10 @@ public sealed class Day12 : Day
     public Day12() : base(2016, 12, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day13.cs b/AOC2016/Day13.cs
index 92fc338..b47ab83 100644
--- a/AOC2016/Day13.cs
+++ b/AOC2016/Day13.cs
@@ -8,6 +8,10 @@ public sealed class Day13 : Day
     public Day13() : base(2016, 13, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day14.cs b/AOC2016/Day14.cs
index dfe5e2b..1b2f370 100644
--- a/AOC2016/Day14.cs
+++ b/AOC2016/Day14.cs
@@ -8,6 +8,10 @@ public sealed class Day14 : Day
     public Day14() : base(2016, 14, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day15.cs b/AOC2016/Day15.cs
index a4de96c..848eb89 100644
--- a/AOC2016/Day15.cs
+++ b/AOC2016/Day15.cs
@@ -8,6 +8,10 @@ public sealed class Day15 : Day
     public Day15() : base(2016, 15, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day16.cs b/AOC2016/Day16.cs
index b1607ff..327a08e 100644
--- a/AOC2016/Day16.cs
+++ b/AOC2016/Day16.cs
@@ -8,6 +8,10 @@ public sealed class Day16 : Day
     public Day16() : base(2016, 16, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day17.cs b/AOC2016/Day17.cs
index b9728a2..3dbfdde 100644
--- a/AOC2016/Day17.cs
+++ b/AOC2016/Day17.cs
@@ -8,6 +8,10 @@ public sealed class Day17 : Day
     public Day17() : base(2016, 17, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day18.cs b/AOC2016/Day18.cs
index 2b4d3c0..920d7aa 100644
--- a/AOC2016/Day18.cs
+++ b/AOC2016/Day18.cs
@@ -8,6 +8,10 @@ public sealed class Day18 : Day
     public Day18() : base(2016, 18, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day19.cs b/AOC2016/Day19.cs
index 607e32e..04038db 100644
--- a/AOC2016/Day19.cs
+++ b/AOC2016/Day19.cs
@@ -8,6 +8,10 @@ public sealed class Day19 : Day
     public Day19() : base(2016, 19, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day20.cs b/AOC2016/Day20.cs
index e993269..4799aec 100644
--- a/AOC2016/Day20.cs
+++ b/AOC2016/Day20.cs
@@ -8,6 +8,10 @@ public sealed class Day20 : Day
     public Day20() : base(2016, 20, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day21.cs b/AOC2016/Day21.cs
index 4b9268d..cf0427b 100644
--- a/AOC2016/Day21.cs
+++ b/AOC2016/Day21.cs
@@ -8,6 +8,10 @@ public sealed class Day21 : Day
     public Day21() : base(2016, 21, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day22.cs b/AOC2016/Day22.cs
index 15b0961..5adc5e8 100644
--- a/AOC2016/Day22.cs
+++ b/AOC2016/Day22.cs
@@ -8,7 +8,11 @@ public sealed class Day22 : Day
     public Day22() : base(2016, 22, "Puzzle Name")
     {
     }
-
+    
+    public override void ProcessInput()
+    {
+    }
+    
     public override object Part1() => "";
 
     public override object Part2() => "";
diff --git a/AOC2016/Day23.cs b/AOC2016/Day23.cs
index 54b1a33..d9bbae0 100644
--- a/AOC2016/Day23.cs
+++ b/AOC2016/Day23.cs
@@ -8,6 +8,10 @@ public sealed class Day23 : Day
     public Day23() : base(2016, 23, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day24.cs b/AOC2016/Day24.cs
index 29fcf5d..533d8f9 100644
--- a/AOC2016/Day24.cs
+++ b/AOC2016/Day24.cs
@@ -8,6 +8,10 @@ public sealed class Day24 : Day
     public Day24() : base(2016, 24, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2016/Day25.cs b/AOC2016/Day25.cs
index 10782ed..d1a25e4 100644
--- a/AOC2016/Day25.cs
+++ b/AOC2016/Day25.cs
@@ -8,6 +8,10 @@ public sealed class Day25 : Day
     public Day25() : base(2016, 25, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day01.cs b/AOC2017/Day01.cs
index 4ce7090..aad889e 100644
--- a/AOC2017/Day01.cs
+++ b/AOC2017/Day01.cs
@@ -8,6 +8,10 @@ public sealed class Day01 : Day
     public Day01() : base(2017, 1, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day02.cs b/AOC2017/Day02.cs
index c288e48..0b1ad79 100644
--- a/AOC2017/Day02.cs
+++ b/AOC2017/Day02.cs
@@ -8,6 +8,10 @@ public sealed class Day02 : Day
     public Day02() : base(2017, 2, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day03.cs b/AOC2017/Day03.cs
index fbee83d..b0c9b50 100644
--- a/AOC2017/Day03.cs
+++ b/AOC2017/Day03.cs
@@ -8,6 +8,10 @@ public sealed class Day03 : Day
     public Day03() : base(2017, 3, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day04.cs b/AOC2017/Day04.cs
index 4028441..d9b32b0 100644
--- a/AOC2017/Day04.cs
+++ b/AOC2017/Day04.cs
@@ -8,6 +8,10 @@ public sealed class Day04 : Day
     public Day04() : base(2017, 4, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day05.cs b/AOC2017/Day05.cs
index f6165f8..fc5133a 100644
--- a/AOC2017/Day05.cs
+++ b/AOC2017/Day05.cs
@@ -8,6 +8,10 @@ public sealed class Day05 : Day
     public Day05() : base(2017, 5, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day06.cs b/AOC2017/Day06.cs
index a89a6c8..9797143 100644
--- a/AOC2017/Day06.cs
+++ b/AOC2017/Day06.cs
@@ -8,6 +8,10 @@ public sealed class Day06 : Day
     public Day06() : base(2017, 6, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day07.cs b/AOC2017/Day07.cs
index eb293a7..651d2ef 100644
--- a/AOC2017/Day07.cs
+++ b/AOC2017/Day07.cs
@@ -8,6 +8,10 @@ public sealed class Day07 : Day
     public Day07() : base(2017, 7, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day08.cs b/AOC2017/Day08.cs
index a3058ea..82f123b 100644
--- a/AOC2017/Day08.cs
+++ b/AOC2017/Day08.cs
@@ -8,6 +8,10 @@ public sealed class Day08 : Day
     public Day08() : base(2017, 8, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day09.cs b/AOC2017/Day09.cs
index 5a0faf5..3bfcef0 100644
--- a/AOC2017/Day09.cs
+++ b/AOC2017/Day09.cs
@@ -8,6 +8,10 @@ public sealed class Day09 : Day
     public Day09() : base(2017, 9, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day10.cs b/AOC2017/Day10.cs
index 743a3c0..067f1de 100644
--- a/AOC2017/Day10.cs
+++ b/AOC2017/Day10.cs
@@ -8,6 +8,10 @@ public sealed class Day10 : Day
     public Day10() : base(2017, 10, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day11.cs b/AOC2017/Day11.cs
index af90f67..972fcee 100644
--- a/AOC2017/Day11.cs
+++ b/AOC2017/Day11.cs
@@ -8,6 +8,10 @@ public sealed class Day11 : Day
     public Day11() : base(2017, 11, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day12.cs b/AOC2017/Day12.cs
index 2b11e3a..9a2b498 100644
--- a/AOC2017/Day12.cs
+++ b/AOC2017/Day12.cs
@@ -8,6 +8,10 @@ public sealed class Day12 : Day
     public Day12() : base(2017, 12, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day13.cs b/AOC2017/Day13.cs
index 7fbb9e5..84a6cc1 100644
--- a/AOC2017/Day13.cs
+++ b/AOC2017/Day13.cs
@@ -8,6 +8,10 @@ public sealed class Day13 : Day
     public Day13() : base(2017, 13, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day14.cs b/AOC2017/Day14.cs
index 97487d7..3c75a61 100644
--- a/AOC2017/Day14.cs
+++ b/AOC2017/Day14.cs
@@ -8,6 +8,10 @@ public sealed class Day14 : Day
     public Day14() : base(2017, 14, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day15.cs b/AOC2017/Day15.cs
index c000bf4..b646e1d 100644
--- a/AOC2017/Day15.cs
+++ b/AOC2017/Day15.cs
@@ -8,6 +8,10 @@ public sealed class Day15 : Day
     public Day15() : base(2017, 15, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day16.cs b/AOC2017/Day16.cs
index 35cc4fc..4f00665 100644
--- a/AOC2017/Day16.cs
+++ b/AOC2017/Day16.cs
@@ -8,6 +8,10 @@ public sealed class Day16 : Day
     public Day16() : base(2017, 16, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day17.cs b/AOC2017/Day17.cs
index 6c1955a..bd4a812 100644
--- a/AOC2017/Day17.cs
+++ b/AOC2017/Day17.cs
@@ -8,6 +8,10 @@ public sealed class Day17 : Day
     public Day17() : base(2017, 17, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day18.cs b/AOC2017/Day18.cs
index db3b2d9..54eaa27 100644
--- a/AOC2017/Day18.cs
+++ b/AOC2017/Day18.cs
@@ -8,6 +8,10 @@ public sealed class Day18 : Day
     public Day18() : base(2017, 18, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day19.cs b/AOC2017/Day19.cs
index 3ec0fbe..7a685b8 100644
--- a/AOC2017/Day19.cs
+++ b/AOC2017/Day19.cs
@@ -8,6 +8,10 @@ public sealed class Day19 : Day
     public Day19() : base(2017, 19, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day20.cs b/AOC2017/Day20.cs
index fca7b19..1c66fe9 100644
--- a/AOC2017/Day20.cs
+++ b/AOC2017/Day20.cs
@@ -8,6 +8,10 @@ public sealed class Day20 : Day
     public Day20() : base(2017, 20, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day21.cs b/AOC2017/Day21.cs
index 5701609..e8b35ad 100644
--- a/AOC2017/Day21.cs
+++ b/AOC2017/Day21.cs
@@ -8,6 +8,10 @@ public sealed class Day21 : Day
     public Day21() : base(2017, 21, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day22.cs b/AOC2017/Day22.cs
index a168da1..997c0a6 100644
--- a/AOC2017/Day22.cs
+++ b/AOC2017/Day22.cs
@@ -8,6 +8,10 @@ public sealed class Day22 : Day
     public Day22() : base(2017, 22, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day23.cs b/AOC2017/Day23.cs
index e9581d8..4032c1a 100644
--- a/AOC2017/Day23.cs
+++ b/AOC2017/Day23.cs
@@ -8,6 +8,10 @@ public sealed class Day23 : Day
     public Day23() : base(2017, 23, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day24.cs b/AOC2017/Day24.cs
index 29306a5..feb23fa 100644
--- a/AOC2017/Day24.cs
+++ b/AOC2017/Day24.cs
@@ -8,6 +8,10 @@ public sealed class Day24 : Day
     public Day24() : base(2017, 24, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2017/Day25.cs b/AOC2017/Day25.cs
index 749432f..c4cf67e 100644
--- a/AOC2017/Day25.cs
+++ b/AOC2017/Day25.cs
@@ -8,6 +8,10 @@ public sealed class Day25 : Day
     public Day25() : base(2017, 25, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day01.cs b/AOC2018/Day01.cs
index 4343c3b..d33edad 100644
--- a/AOC2018/Day01.cs
+++ b/AOC2018/Day01.cs
@@ -8,6 +8,10 @@ public sealed class Day01 : Day
     public Day01() : base(2018, 1, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day02.cs b/AOC2018/Day02.cs
index 1070fdf..07b33f0 100644
--- a/AOC2018/Day02.cs
+++ b/AOC2018/Day02.cs
@@ -8,6 +8,10 @@ public sealed class Day02 : Day
     public Day02() : base(2018, 2, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day03.cs b/AOC2018/Day03.cs
index 8d201e6..6bd904f 100644
--- a/AOC2018/Day03.cs
+++ b/AOC2018/Day03.cs
@@ -8,6 +8,10 @@ public sealed class Day03 : Day
     public Day03() : base(2018, 3, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day04.cs b/AOC2018/Day04.cs
index 1d9bef7..f5bfc6b 100644
--- a/AOC2018/Day04.cs
+++ b/AOC2018/Day04.cs
@@ -8,6 +8,10 @@ public sealed class Day04 : Day
     public Day04() : base(2018, 4, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day05.cs b/AOC2018/Day05.cs
index 0509574..a2ede6e 100644
--- a/AOC2018/Day05.cs
+++ b/AOC2018/Day05.cs
@@ -8,6 +8,10 @@ public sealed class Day05 : Day
     public Day05() : base(2018, 5, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day06.cs b/AOC2018/Day06.cs
index 62f3022..b67ff07 100644
--- a/AOC2018/Day06.cs
+++ b/AOC2018/Day06.cs
@@ -8,6 +8,10 @@ public sealed class Day06 : Day
     public Day06() : base(2018, 6, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day07.cs b/AOC2018/Day07.cs
index 9036bb1..2efd4b6 100644
--- a/AOC2018/Day07.cs
+++ b/AOC2018/Day07.cs
@@ -8,6 +8,10 @@ public sealed class Day07 : Day
     public Day07() : base(2018, 7, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day08.cs b/AOC2018/Day08.cs
index 3db2eaf..b5cb494 100644
--- a/AOC2018/Day08.cs
+++ b/AOC2018/Day08.cs
@@ -8,6 +8,10 @@ public sealed class Day08 : Day
     public Day08() : base(2018, 8, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day09.cs b/AOC2018/Day09.cs
index 9b492cb..fffc8b4 100644
--- a/AOC2018/Day09.cs
+++ b/AOC2018/Day09.cs
@@ -8,6 +8,10 @@ public sealed class Day09 : Day
     public Day09() : base(2018, 9, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day10.cs b/AOC2018/Day10.cs
index 2563fd6..2fdac05 100644
--- a/AOC2018/Day10.cs
+++ b/AOC2018/Day10.cs
@@ -8,6 +8,10 @@ public sealed class Day10 : Day
     public Day10() : base(2018, 10, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day11.cs b/AOC2018/Day11.cs
index 18472b8..d2869c5 100644
--- a/AOC2018/Day11.cs
+++ b/AOC2018/Day11.cs
@@ -8,6 +8,10 @@ public sealed class Day11 : Day
     public Day11() : base(2018, 11, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day12.cs b/AOC2018/Day12.cs
index ea0e833..1556693 100644
--- a/AOC2018/Day12.cs
+++ b/AOC2018/Day12.cs
@@ -8,6 +8,10 @@ public sealed class Day12 : Day
     public Day12() : base(2018, 12, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day13.cs b/AOC2018/Day13.cs
index 7fac808..69c00a2 100644
--- a/AOC2018/Day13.cs
+++ b/AOC2018/Day13.cs
@@ -8,6 +8,10 @@ public sealed class Day13 : Day
     public Day13() : base(2018, 13, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day14.cs b/AOC2018/Day14.cs
index d3fffcf..dcf173d 100644
--- a/AOC2018/Day14.cs
+++ b/AOC2018/Day14.cs
@@ -8,6 +8,10 @@ public sealed class Day14 : Day
     public Day14() : base(2018, 14, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day15.cs b/AOC2018/Day15.cs
index 82a60ce..fc0f59a 100644
--- a/AOC2018/Day15.cs
+++ b/AOC2018/Day15.cs
@@ -8,6 +8,10 @@ public sealed class Day15 : Day
     public Day15() : base(2018, 15, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day16.cs b/AOC2018/Day16.cs
index a491ef6..705cfa9 100644
--- a/AOC2018/Day16.cs
+++ b/AOC2018/Day16.cs
@@ -8,6 +8,10 @@ public sealed class Day16 : Day
     public Day16() : base(2018, 16, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day17.cs b/AOC2018/Day17.cs
index 159294d..9f9e35a 100644
--- a/AOC2018/Day17.cs
+++ b/AOC2018/Day17.cs
@@ -8,6 +8,10 @@ public sealed class Day17 : Day
     public Day17() : base(2018, 17, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day18.cs b/AOC2018/Day18.cs
index 6687249..8296881 100644
--- a/AOC2018/Day18.cs
+++ b/AOC2018/Day18.cs
@@ -8,6 +8,10 @@ public sealed class Day18 : Day
     public Day18() : base(2018, 18, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day19.cs b/AOC2018/Day19.cs
index fc7312e..89659a3 100644
--- a/AOC2018/Day19.cs
+++ b/AOC2018/Day19.cs
@@ -8,6 +8,10 @@ public sealed class Day19 : Day
     public Day19() : base(2018, 19, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day20.cs b/AOC2018/Day20.cs
index e586737..d531376 100644
--- a/AOC2018/Day20.cs
+++ b/AOC2018/Day20.cs
@@ -8,6 +8,10 @@ public sealed class Day20 : Day
     public Day20() : base(2018, 20, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day21.cs b/AOC2018/Day21.cs
index 4b7b352..3269319 100644
--- a/AOC2018/Day21.cs
+++ b/AOC2018/Day21.cs
@@ -8,6 +8,10 @@ public sealed class Day21 : Day
     public Day21() : base(2018, 21, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day22.cs b/AOC2018/Day22.cs
index c2d3dc7..6c13a45 100644
--- a/AOC2018/Day22.cs
+++ b/AOC2018/Day22.cs
@@ -8,6 +8,10 @@ public sealed class Day22 : Day
     public Day22() : base(2018, 22, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day23.cs b/AOC2018/Day23.cs
index 5ef7793..c0b49bd 100644
--- a/AOC2018/Day23.cs
+++ b/AOC2018/Day23.cs
@@ -8,6 +8,10 @@ public sealed class Day23 : Day
     public Day23() : base(2018, 23, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day24.cs b/AOC2018/Day24.cs
index 76519bc..18cd3a6 100644
--- a/AOC2018/Day24.cs
+++ b/AOC2018/Day24.cs
@@ -8,6 +8,10 @@ public sealed class Day24 : Day
     public Day24() : base(2018, 24, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2018/Day25.cs b/AOC2018/Day25.cs
index 3a3af58..2912111 100644
--- a/AOC2018/Day25.cs
+++ b/AOC2018/Day25.cs
@@ -8,6 +8,10 @@ public sealed class Day25 : Day
     public Day25() : base(2018, 25, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() => "";
 
diff --git a/AOC2019/Day01.cs b/AOC2019/Day01.cs
index 7362e57..9b0520c 100644
--- a/AOC2019/Day01.cs
+++ b/AOC2019/Day01.cs
@@ -2,9 +2,13 @@ namespace AOC2019;
 
 public sealed class Day01 : Day
 {
-    private readonly IEnumerable<int> _masses;
+    private IEnumerable<int>? _masses;
 
     public Day01() : base(2019, 1, "The Tyranny of the Rocket Equation")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _masses = Input.Select(int.Parse);
     }
@@ -24,7 +28,7 @@ public sealed class Day01 : Day
         return total;
     }
 
-    public override object Part1() => _masses.Sum(FuelCost);
+    public override object Part1() => _masses!.Sum(FuelCost);
 
-    public override object Part2() => _masses.Sum(FullCost);
+    public override object Part2() => _masses!.Sum(FullCost);
 }
diff --git a/AOC2019/Day02.cs b/AOC2019/Day02.cs
index aeb45d1..8fb9b57 100644
--- a/AOC2019/Day02.cs
+++ b/AOC2019/Day02.cs
@@ -2,16 +2,20 @@ namespace AOC2019;
 
 public sealed class Day02 : Day
 {
-    private readonly IEnumerable<int> _input;
+    private IEnumerable<int>? _input;
 
     public Day02() : base(2019, 2, "1202 Program Alarm")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _input = Input.First().Split(',').Select(int.Parse);
     }
 
     private int RunIntCode(int noun, int verb)
     {
-        var v = _input.ToList();
+        var v = _input!.ToList();
         v[1] = noun;
         v[2] = verb;
 
diff --git a/AOC2019/Day03.cs b/AOC2019/Day03.cs
index 527fd4f..4cc3bf3 100644
--- a/AOC2019/Day03.cs
+++ b/AOC2019/Day03.cs
@@ -2,21 +2,25 @@ namespace AOC2019;
 
 public sealed class Day03 : Day
 {
-    private readonly IEnumerable<(int, int)> _intersections;
-    private readonly List<Dictionary<(int, int), int>> _wires;
+    private IEnumerable<(int, int)>? _intersections;
+    private List<Dictionary<(int, int), int>>? _wires;
 
     public Day03() : base(2019, 3, "Crossed Wires")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _wires = Input.Select(ParseWire).ToList();
         _intersections = _wires[0].Keys.Intersect(_wires[1].Keys);
     }
 
-    public override object Part1() => 
-        _intersections.Min(x => Math.Abs(x.Item1) + Math.Abs(x.Item2));
+    public override object Part1() =>
+        _intersections!.Min(x => Math.Abs(x.Item1) + Math.Abs(x.Item2));
 
     public override object Part2() =>
         // add 2 to count (0, 0) on both lines
-        _intersections.Min(x => _wires[0][x] + _wires[1][x]) + 2;
+        _intersections!.Min(x => _wires![0][x] + _wires[1][x]) + 2;
 
     private static Dictionary<(int, int), int> ParseWire(string line)
     {
@@ -45,4 +49,4 @@ public sealed class Day03 : Day
 
         return r;
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day04.cs b/AOC2019/Day04.cs
index 2f595b4..193f12f 100644
--- a/AOC2019/Day04.cs
+++ b/AOC2019/Day04.cs
@@ -2,9 +2,13 @@ namespace AOC2019;
 
 public sealed class Day04 : Day
 {
-    private readonly int _start, _end;
+    private int _start, _end;
 
     public Day04() : base(2019, 4, "Secure Container")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var range = Input.First().Split('-').Select(int.Parse).ToList();
         _start = range[0];
@@ -34,6 +38,6 @@ public sealed class Day04 : Day
     public override object Part1() =>
         Enumerable.Range(_start, _end).Count(IsValid);
 
-    public override object Part2() => 
+    public override object Part2() =>
         Enumerable.Range(_start, _end).Count(HasOnePair);
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day05.cs b/AOC2019/Day05.cs
index 9c3f4d4..9e94f45 100644
--- a/AOC2019/Day05.cs
+++ b/AOC2019/Day05.cs
@@ -2,10 +2,14 @@ namespace AOC2019;
 
 public sealed class Day05 : Day
 {
-    private readonly IEnumerable<int> _tape;
+    private IEnumerable<int>? _tape;
     private int _output;
 
     public Day05() : base(2019, 5, "Sunny with a Chance of Asteroids")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _tape = Input.First().Split(',').Select(int.Parse);
     }
@@ -61,13 +65,13 @@ public sealed class Day05 : Day
 
     public override object Part1()
     {
-        RunIntCode(_tape.ToList(), 1);
+        RunIntCode(_tape!.ToList(), 1);
         return _output;
     }
 
     public override object Part2()
     {
-        RunIntCode(_tape.ToList(), 5);
+        RunIntCode(_tape!.ToList(), 5);
         return _output;
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day06.cs b/AOC2019/Day06.cs
index ebf0e27..5fcd28e 100644
--- a/AOC2019/Day06.cs
+++ b/AOC2019/Day06.cs
@@ -2,9 +2,13 @@ namespace AOC2019;
 
 public sealed class Day06 : Day
 {
-    private readonly Dictionary<string, string> _input;
+    private Dictionary<string, string>? _input;
 
     public Day06() : base(2019, 6, "Universal Orbit Map")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _input = Input.ToDictionary(i => i.Split(')')[1], i => i.Split(')')[0]);
     }
@@ -12,14 +16,14 @@ public sealed class Day06 : Day
     private List<string> GetParents(string obj)
     {
         var res = new List<string>();
-        for (var curr = obj; curr != "COM"; curr = _input[curr])
+        for (var curr = obj; curr != "COM"; curr = _input![curr])
             res.Add(curr);
         res.Add("COM");
         return res;
     }
 
     public override object Part1() =>
-        _input.Keys.Sum(o => GetParents(o).Count - 1);
+        _input!.Keys.Sum(o => GetParents(o).Count - 1);
 
     public override object Part2()
     {
@@ -32,4 +36,4 @@ public sealed class Day06 : Day
 
         return you.Count + san.Count - common * 2;
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day07.cs b/AOC2019/Day07.cs
index 14e4b0b..c0fc484 100644
--- a/AOC2019/Day07.cs
+++ b/AOC2019/Day07.cs
@@ -5,6 +5,10 @@ public sealed class Day07 : Day
     private readonly IntCodeVM[] _amplifiers = new IntCodeVM[5];
 
     public Day07() : base(2019, 7, "Amplification Circuit")
+    {
+    }
+
+    public override void ProcessInput()
     {
         for (var i = 0; i < 5; i++) _amplifiers[i] = new(Input.First());
     }
diff --git a/AOC2019/Day08.cs b/AOC2019/Day08.cs
index 056a616..6842d16 100644
--- a/AOC2019/Day08.cs
+++ b/AOC2019/Day08.cs
@@ -2,23 +2,27 @@ namespace AOC2019;
 
 public sealed class Day08 : Day
 {
-    private readonly List<List<char>> _photo;
+    private List<List<char>>? _photo;
 
     public Day08() : base(2019, 8, "Space Image Format")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _photo = Input.First().Chunk(25 * 6).Select(s => s.ToList()).ToList();
     }
 
     public override object Part1()
     {
-        var l = _photo.OrderBy(layer => layer.Count(pixel => pixel == '0')).First();
+        var l = _photo!.OrderBy(layer => layer.Count(pixel => pixel == '0')).First();
         return l.Count(p => p == '1') * l.Count(p => p == '2');
     }
 
     public override object Part2()
     {
         return Enumerable.Range(0, 25 * 6)
-            .Select(p => Enumerable.Range(0, _photo.Count)
+            .Select(p => Enumerable.Range(0, _photo!.Count)
                 .Select(l => _photo[l][p])
                 .Aggregate('2', (acc, next) =>
                     acc != '2' ? acc : next == '0' ? ' ' : next
@@ -30,4 +34,4 @@ public sealed class Day08 : Day
             .ToDelimitedString("\n")
             .Replace('1', 'x');
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day09.cs b/AOC2019/Day09.cs
index 8c81bf0..b669acf 100644
--- a/AOC2019/Day09.cs
+++ b/AOC2019/Day09.cs
@@ -2,24 +2,28 @@ namespace AOC2019;
 
 public sealed class Day09 : Day
 {
-    private readonly IntCodeVM _vm;
+    private IntCodeVM? _vm;
 
     public Day09() : base(2019, 9, "Sensor Boost")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _vm = new(Input.First());
     }
 
     public override object Part1()
     {
-        _vm.Reset();
+        _vm!.Reset();
         _vm.Run(1);
         return _vm.Output.ToDelimitedString(",");
     }
 
     public override object Part2()
     {
-        _vm.Reset();
+        _vm!.Reset();
         _vm.Run(2);
         return _vm.Output.ToDelimitedString(",");
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day10.cs b/AOC2019/Day10.cs
index d078d57..cfbbbc6 100644
--- a/AOC2019/Day10.cs
+++ b/AOC2019/Day10.cs
@@ -2,11 +2,15 @@ namespace AOC2019;
 
 public sealed class Day10 : Day
 {
-    private readonly HashSet<(int x, int y)> _asteroids;
+    private HashSet<(int x, int y)>? _asteroids;
     private (int x, int y) _best = (x: -1, y: -1);
     private int _bestCanSee;
 
     public Day10() : base(2019, 10, "Monitoring Station")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _asteroids = Input
             .Select((r, y) => r.Select((c, x) => (x, y, isAsteroid: c == '#')).ToArray())
@@ -18,7 +22,7 @@ public sealed class Day10 : Day
 
     public override object Part1()
     {
-        foreach (var asteroid in _asteroids)
+        foreach (var asteroid in _asteroids!)
         {
             var canSee = _asteroids
                 .Except(new[] { asteroid })
@@ -44,7 +48,7 @@ public sealed class Day10 : Day
             if (q.Count > 0) yield return q.Dequeue();
         }
 
-        return _asteroids
+        return _asteroids!
             .Where(a => a != _best)
             .Select(a =>
             {
@@ -63,4 +67,4 @@ public sealed class Day10 : Day
             .Select(a => a.x * 100 + a.y)
             .Single();
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day11.cs b/AOC2019/Day11.cs
index 8aafd22..c1910aa 100644
--- a/AOC2019/Day11.cs
+++ b/AOC2019/Day11.cs
@@ -2,11 +2,15 @@ namespace AOC2019;
 
 public sealed class Day11 : Day
 {
-    private readonly IntCodeVM _vm;
+    private IntCodeVM? _vm;
     private Direction _heading;
     private long _x, _y;
 
     public Day11() : base(2019, 11, "Space Police")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _vm = new(Input.First());
     }
@@ -49,7 +53,7 @@ public sealed class Day11 : Day
     private Dictionary<(long x, long y), long> PaintShip(int initialVal)
     {
         var map = new Dictionary<(long, long), long>();
-        _vm.Reset();
+        _vm!.Reset();
         _heading = Direction.Up;
         _x = 0;
         _y = 0;
diff --git a/AOC2019/Day12.cs b/AOC2019/Day12.cs
index 64998b4..457f870 100644
--- a/AOC2019/Day12.cs
+++ b/AOC2019/Day12.cs
@@ -2,10 +2,14 @@ namespace AOC2019;
 
 public sealed class Day12 : Day
 {
-    private readonly List<Position> _moons;
+    private List<Position>? _moons;
     private int _step;
 
     public Day12() : base(2019, 12, "The N-Body Problem")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _moons = Input
             .Select(moon =>
@@ -24,7 +28,7 @@ public sealed class Day12 : Day
 
     private void Step()
     {
-        foreach (var moon in _moons)
+        foreach (var moon in _moons!)
             moon.Gravitate();
 
         foreach (var moon in _moons)
@@ -38,7 +42,7 @@ public sealed class Day12 : Day
         while (_step < 1000)
             Step();
 
-        return _moons.Sum(p => p.TotalEnergy);
+        return _moons!.Sum(p => p.TotalEnergy);
     }
 
     public override object Part2()
@@ -48,9 +52,9 @@ public sealed class Day12 : Day
         while (cycleX == 0 || cycleY == 0 || cycleZ == 0)
         {
             Step();
-            if (cycleX == 0 && _moons.All(m => m.Dx == 0)) cycleX = _step * 2;
-            if (cycleY == 0 && _moons.All(m => m.Dy == 0)) cycleY = _step * 2;
-            if (cycleZ == 0 && _moons.All(m => m.Dz == 0)) cycleZ = _step * 2;
+            if (cycleX == 0 && _moons!.All(m => m.Dx == 0)) cycleX = _step * 2;
+            if (cycleY == 0 && _moons!.All(m => m.Dy == 0)) cycleY = _step * 2;
+            if (cycleZ == 0 && _moons!.All(m => m.Dz == 0)) cycleZ = _step * 2;
         }
 
         return Util.Lcm(cycleX, Util.Lcm(cycleY, cycleZ));
@@ -58,9 +62,9 @@ public sealed class Day12 : Day
 
     public class Position
     {
-        public int Dx, Dy, Dz;
         private List<Position> _siblings;
         private int _x, _y, _z;
+        public int Dx, Dy, Dz;
 
         public Position(IList<int> moon)
         {
@@ -105,4 +109,4 @@ public sealed class Day12 : Day
             _z += Dz;
         }
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2019/Day13.cs b/AOC2019/Day13.cs
index 0fa232e..759cc7d 100644
--- a/AOC2019/Day13.cs
+++ b/AOC2019/Day13.cs
@@ -3,9 +3,13 @@ namespace AOC2019;
 public sealed class Day13 : Day
 {
     private readonly Dictionary<(int x, int y), int> _board = new();
-    private readonly IntCodeVM _vm;
+    private IntCodeVM? _vm;
 
     public Day13() : base(2019, 13, "Care Package")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _vm = new(Input.First());
     }
@@ -44,14 +48,14 @@ public sealed class Day13 : Day
 
     public override object Part1()
     {
-        _vm.Reset();
+        _vm!.Reset();
         _vm.Run();
         return _vm.Output.Where((v, i) => (i + 1) % 3 == 0 && v == 2).Count();
     }
 
     public override object Part2()
     {
-        _vm.Reset();
+        _vm!.Reset();
         _vm.Memory[0] = 2;
         var printBoard = false;
         var gameTicks = 0;
diff --git a/AOC2019/Day14.cs b/AOC2019/Day14.cs
index da88bb0..8f2dc48 100644
--- a/AOC2019/Day14.cs
+++ b/AOC2019/Day14.cs
@@ -2,17 +2,18 @@ namespace AOC2019;
 
 public sealed class Day14 : Day
 {
-    private readonly Dictionary<string, Reaction> _reactions;
-
-    private Dictionary<string, long> _available;
+    private Dictionary<string, Reaction>? _reactions;
+    private Dictionary<string, long> _available = new();
 
     public Day14() : base(2019, 14, "Space Stoichiometry")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _reactions = Input
             .Select(Reaction.Parse)
             .ToDictionary(r => r.Product.Name);
-        
-        _available = new();
     }
 
     private bool Consume(string chem, long quantity)
@@ -35,7 +36,7 @@ public sealed class Day14 : Day
         if (chem == "ORE")
             return false;
 
-        var reaction = _reactions[chem];
+        var reaction = _reactions![chem];
         var reactionCount = (long)Math.Ceiling((double)quantity / reaction.Product.Quantity);
 
         if (reaction.Reactants.Any(reactant => !Consume(reactant.Name, reactionCount * reactant.Quantity)))
diff --git a/AOC2019/Day15.cs b/AOC2019/Day15.cs
index 4bb1b44..b626948 100644
--- a/AOC2019/Day15.cs
+++ b/AOC2019/Day15.cs
@@ -3,16 +3,20 @@ namespace AOC2019;
 public sealed class Day15 : Day
 {
     private readonly bool _verbose = false;
-    private readonly IntCodeVM _vm;
+    private IntCodeVM? _vm;
 
     public Day15() : base(2019, 15, "Oxygen System")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _vm = new(Input.First());
     }
 
     public override object Part1()
     {
-        _vm.Reset();
+        _vm!.Reset();
         var currentLocation = new Location(0, 0);
         var halt = IntCodeVM.HaltType.Waiting;
         while (halt == IntCodeVM.HaltType.Waiting)
@@ -128,9 +132,9 @@ public sealed class Day15 : Day
         public static readonly Dictionary<(int x, int y), Location> AllLocations = new();
 
         private readonly int _currentType;
-        public int DistanceToOxygenSystem = int.MaxValue - 1;
 
         private int _searchDirection = 1;
+        public int DistanceToOxygenSystem = int.MaxValue - 1;
 
         public Location(int x, int y, int prev = 0, int type = Empty)
         {
diff --git a/AOC2019/Day16.cs b/AOC2019/Day16.cs
index 2e49f58..b79c43d 100644
--- a/AOC2019/Day16.cs
+++ b/AOC2019/Day16.cs
@@ -3,17 +3,20 @@ namespace AOC2019;
 public sealed class Day16 : Day
 {
     private static readonly int[] BasePattern = { 0, 1, 0, -1 };
-    private readonly int[] _initialList;
+    private int[]? _initialList;
 
     public Day16() : base(2019, 16, "Flawed Frequency Transmission")
     {
+    }
+    
+    public override void ProcessInput(){
         _initialList = Input.First().Select(c => int.Parse($"{c}")).ToArray();
     }
 
     public override object Part1()
     {
         const int phaseCount = 100;
-        var signal0 = _initialList.ToArray();
+        var signal0 = _initialList!.ToArray();
         var signal1 = new int[signal0.Length];
 
         for (var i = 0; i < phaseCount; i++)
@@ -27,8 +30,8 @@ public sealed class Day16 : Day
     public override object Part2()
     {
         const int phaseCount = 100;
-        var messageOffset = _initialList.Take(7).Aggregate((n, i) => n * 10 + i);
-        var signal = _initialList.Repeat(10_000).Skip(messageOffset).ToArray();
+        var messageOffset = _initialList!.Take(7).Aggregate((n, i) => n * 10 + i);
+        var signal = _initialList!.Repeat(10_000).Skip(messageOffset).ToArray();
 
         for (var p = 0; p < phaseCount; p++)
         {
diff --git a/AOC2019/Day17.cs b/AOC2019/Day17.cs
index 661080d..fb5b1e2 100644
--- a/AOC2019/Day17.cs
+++ b/AOC2019/Day17.cs
@@ -2,16 +2,20 @@ namespace AOC2019;
 
 public sealed class Day17 : Day
 {
-    private readonly IntCodeVM _vm;
+    private IntCodeVM? _vm;
 
     public Day17() : base(2019, 17, "Set and Forget")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _vm = new(Input.First());
     }
 
     public override object Part1()
     {
-        _vm.Reset();
+        _vm!.Reset();
         _vm.Run();
         var sb = new StringBuilder();
         while (_vm.Output.Any())
diff --git a/AOC2019/Day18.cs b/AOC2019/Day18.cs
index 7312802..bba470d 100644
--- a/AOC2019/Day18.cs
+++ b/AOC2019/Day18.cs
@@ -6,6 +6,10 @@ public sealed class Day18 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         return "";
diff --git a/AOC2019/Day19.cs b/AOC2019/Day19.cs
index 23c15a2..0219fa6 100644
--- a/AOC2019/Day19.cs
+++ b/AOC2019/Day19.cs
@@ -2,11 +2,14 @@ namespace AOC2019;
 
 public sealed class Day19 : Day
 {
-    private readonly long[,] _grid;
-    private readonly IntCodeVM _vm;
+    private long[,]? _grid;
+    private IntCodeVM? _vm;
 
     public Day19() : base(2019, 19, "Tractor Beam")
     {
+    }
+
+    public override void ProcessInput(){
         _vm = new(Input.First());
         _grid = new long[50, 50];
     }
@@ -16,12 +19,12 @@ public sealed class Day19 : Day
         for (var x = 0; x < 50; x++)
             for (var y = 0; y < 50; y++)
             {
-                _vm.Reset();
+                _vm!.Reset();
                 _vm.Run(x, y);
-                _grid[x, y] = _vm.Result;
+                _grid![x, y] = _vm.Result;
             }
 
-        return _grid.Cast<long>().Sum();
+        return _grid!.Cast<long>().Sum();
     }
 
     public override object Part2()
@@ -30,7 +33,7 @@ public sealed class Day19 : Day
         {
             while (true)
             {
-                _vm.Reset();
+                _vm!.Reset();
                 _vm.Run(x, y);
                 if (_vm.Result == 1) break;
                 y++;
diff --git a/AOC2019/Day20.cs b/AOC2019/Day20.cs
index 9b6097f..15d2205 100644
--- a/AOC2019/Day20.cs
+++ b/AOC2019/Day20.cs
@@ -5,6 +5,10 @@ public sealed class Day20 : Day
     public Day20() : base(2019, 20, "Donut Maze")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2019/Day21.cs b/AOC2019/Day21.cs
index a440d8d..a37ef42 100644
--- a/AOC2019/Day21.cs
+++ b/AOC2019/Day21.cs
@@ -8,6 +8,10 @@ public sealed class Day21 : Day
     {
         _vm = new(Input.First());
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2019/Day22.cs b/AOC2019/Day22.cs
index 1fa73b8..2171ad2 100644
--- a/AOC2019/Day22.cs
+++ b/AOC2019/Day22.cs
@@ -5,6 +5,10 @@ public sealed class Day22 : Day
     public Day22() : base(2019, 22, "Slam Shuffle")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2019/Day23.cs b/AOC2019/Day23.cs
index 9dfe688..1af65e8 100644
--- a/AOC2019/Day23.cs
+++ b/AOC2019/Day23.cs
@@ -5,6 +5,10 @@ public sealed class Day23 : Day
     public Day23() : base(2019, 23, "Category Six")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2019/Day24.cs b/AOC2019/Day24.cs
index 485804f..44329f9 100644
--- a/AOC2019/Day24.cs
+++ b/AOC2019/Day24.cs
@@ -5,6 +5,10 @@ public sealed class Day24 : Day
     public Day24() : base(2019, 24, "Planet of Discord")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2019/Day25.cs b/AOC2019/Day25.cs
index 729027f..b0e9ef4 100644
--- a/AOC2019/Day25.cs
+++ b/AOC2019/Day25.cs
@@ -5,6 +5,10 @@ public sealed class Day25 : Day
     public Day25() : base(2019, 25, "Cryostasis")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1()
     {
diff --git a/AOC2020/Day01.cs b/AOC2020/Day01.cs
index 3dcc32f..de1581a 100644
--- a/AOC2020/Day01.cs
+++ b/AOC2020/Day01.cs
@@ -5,20 +5,26 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day01 : Day
 {
-    private readonly ImmutableHashSet<int> _entries;
+    private ImmutableHashSet<int>? _entries;
 
-    public Day01() : base(2020, 1, "Report Repair") =>
+    public Day01() : base(2020, 1, "Report Repair")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _entries = Input.Select(int.Parse).ToImmutableHashSet();
+    }
 
     public override object Part1()
     {
-        var entry = _entries.First(e => _entries.Contains(2020 - e));
+        var entry = _entries!.First(e => _entries!.Contains(2020 - e));
         return entry * (2020 - entry);
     }
 
     public override object Part2()
     {
-        foreach (var i in _entries)
+        foreach (var i in _entries!)
         foreach (var j in _entries)
         foreach (var k in _entries)
             if (i + j + k == 2020)
diff --git a/AOC2020/Day02.cs b/AOC2020/Day02.cs
index 2d71496..e144170 100644
--- a/AOC2020/Day02.cs
+++ b/AOC2020/Day02.cs
@@ -5,16 +5,22 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day02 : Day
 {
-    private readonly ImmutableList<Password> _passwords;
+    private ImmutableList<Password>? _passwords;
 
-    public Day02() : base(2020, 2, "Password Philosophy") =>
+    public Day02() : base(2020, 2, "Password Philosophy")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _passwords = Input.Select(p => new Password(p)).ToImmutableList();
+    }
 
     public override object Part1() =>
-        _passwords.Count(p => p.IsValid);
+        _passwords!.Count(p => p.IsValid);
 
     public override object Part2() =>
-        _passwords.Count(p => p.IsValidByIndex);
+        _passwords!.Count(p => p.IsValidByIndex);
 
     private class Password
     {
diff --git a/AOC2020/Day03.cs b/AOC2020/Day03.cs
index ebcd1a2..6c2fac8 100644
--- a/AOC2020/Day03.cs
+++ b/AOC2020/Day03.cs
@@ -5,19 +5,21 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day03 : Day
 {
-    private readonly string[] _grid;
-    private readonly int _width;
+    private string[]? _grid;
 
     public Day03() : base(2020, 3, "Toboggan Trajectory")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _grid = Input.ToArray();
-        _width = _grid[0].Length;
     }
 
     private long CountSlope(int dx, int dy)
     {
         long hits = 0;
-        for (int x = 0, y = 0; y < _grid.Length; y += dy, x = (x + dx) % _width)
+        for (int x = 0, y = 0; y < _grid!.Length; y += dy, x = (x + dx) % _grid[0].Length)
             if (_grid[y][x] == '#')
                 hits++;
 
diff --git a/AOC2020/Day04.cs b/AOC2020/Day04.cs
index a3cf01c..669d558 100644
--- a/AOC2020/Day04.cs
+++ b/AOC2020/Day04.cs
@@ -3,11 +3,15 @@ namespace AOC2020;
 /// <summary>
 ///     Day 4: <a href="https://adventofcode.com/2020/day/4" />
 /// </summary>
-public sealed class Day04 : Day
+public sealed partial class Day04 : Day
 {
-    private readonly List<Passport> _passports;
+    private List<Passport>? _passports;
 
     public Day04() : base(2020, 4, "Passport Processing")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _passports = new();
 
@@ -27,11 +31,11 @@ public sealed class Day04 : Day
         if (a.Any()) _passports.Add(Passport.Parse(a));
     }
 
-    public override object Part1() => _passports.Count(p => p.IsValid);
+    public override object Part1() => _passports!.Count(p => p.IsValid);
 
-    public override object Part2() => _passports.Count(p => p.ExtendedValidation());
+    public override object Part2() => _passports!.Count(p => p.ExtendedValidation());
 
-    private class Passport
+    private partial class Passport
     {
         private string? _byr;
         private string? _cid;
@@ -58,7 +62,7 @@ public sealed class Day04 : Day
             // birth year
             if (int.TryParse(_byr, out var byr))
             {
-                if (byr < 1920 || byr > 2002)
+                if (byr is < 1920 or > 2002)
                     return false;
             }
             else
@@ -69,7 +73,7 @@ public sealed class Day04 : Day
             // issuance year
             if (int.TryParse(_iyr, out var iyr))
             {
-                if (iyr < 2010 || iyr > 2020)
+                if (iyr is < 2010 or > 2020)
                     return false;
             }
             else
@@ -80,7 +84,7 @@ public sealed class Day04 : Day
             // expiration year
             if (int.TryParse(_eyr, out var eyr))
             {
-                if (eyr < 2020 || eyr > 2030)
+                if (eyr is < 2020 or > 2030)
                     return false;
             }
             else
@@ -94,7 +98,7 @@ public sealed class Day04 : Day
                 var h = _hgt[..3];
                 if (int.TryParse(h, out var hgt))
                 {
-                    if (hgt < 150 || hgt > 193)
+                    if (hgt is < 150 or > 193)
                         return false;
                 }
                 else
@@ -107,7 +111,7 @@ public sealed class Day04 : Day
                 var h = _hgt[..2];
                 if (int.TryParse(h, out var hgt))
                 {
-                    if (hgt < 59 || hgt > 76)
+                    if (hgt is < 59 or > 76)
                         return false;
                 }
                 else
@@ -121,7 +125,7 @@ public sealed class Day04 : Day
             }
 
             // hair color
-            if (!Regex.IsMatch(_hcl!, "#[0-9a-f]{6}"))
+            if (!HexColor().IsMatch(_hcl!))
                 return false;
 
             // eye color
@@ -169,5 +173,8 @@ public sealed class Day04 : Day
 
             return passport;
         }
+
+        [GeneratedRegex("#[0-9a-f]{6}")]
+        private static partial Regex HexColor();
     }
 }
diff --git a/AOC2020/Day05.cs b/AOC2020/Day05.cs
index 65d9125..93177ac 100644
--- a/AOC2020/Day05.cs
+++ b/AOC2020/Day05.cs
@@ -5,18 +5,24 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day05 : Day
 {
-    private readonly ImmutableHashSet<int> _ids;
+    private ImmutableHashSet<int>? _ids;
 
-    public Day05() : base(2020, 5, "Binary Boarding") =>
+    public Day05() : base(2020, 5, "Binary Boarding")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _ids = Input
             .Select(s =>
                 Convert.ToInt32(s.Replace('F', '0').Replace('B', '1').Replace('L', '0').Replace('R', '1'), 2))
             .OrderBy(i => i)
             .ToImmutableHashSet();
+    }
 
-    public override object Part1() => _ids.Last();
+    public override object Part1() => _ids!.Last();
 
     public override object Part2() =>
         // arithmetic sum of full series
-        (_ids.Count + 1) * (_ids.First() + _ids.Last()) / 2 - _ids.Sum();
+        (_ids!.Count + 1) * (_ids.First() + _ids.Last()) / 2 - _ids.Sum();
 }
diff --git a/AOC2020/Day06.cs b/AOC2020/Day06.cs
index 1702354..43399bd 100644
--- a/AOC2020/Day06.cs
+++ b/AOC2020/Day06.cs
@@ -5,10 +5,14 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day06 : Day
 {
-    private readonly int _countPart1;
-    private readonly int _countPart2;
+    private int _countPart1;
+    private int _countPart2;
 
     public Day06() : base(2020, 6, "Custom Customs")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var alphabet = "abcedfghijklmnopqrstuvwxyz".ToCharArray();
         _countPart1 = 0;
diff --git a/AOC2020/Day07.cs b/AOC2020/Day07.cs
index 080eb98..54fb73f 100644
--- a/AOC2020/Day07.cs
+++ b/AOC2020/Day07.cs
@@ -5,9 +5,14 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day07 : Day
 {
-    private readonly Dictionary<string, IEnumerable<(int Weight, string Name)?>> _rules;
+    private Dictionary<string, IEnumerable<(int Weight, string Name)?>>? _rules;
 
-    public Day07() : base(2020, 7, "Handy Haversacks") =>
+    public Day07() : base(2020, 7, "Handy Haversacks")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _rules = Input
             .Select(rule =>
             {
@@ -17,6 +22,7 @@ public sealed class Day07 : Day
                 return (outer, inner);
             })
             .ToDictionary(t => t.outer, t => t.inner);
+    }
 
     private static (int, string)? ParseQuantity(string arg)
     {
@@ -26,7 +32,7 @@ public sealed class Day07 : Day
     }
 
     private int Weight(string node) =>
-        1 + _rules[node]
+        1 + _rules![node]
             .Where(i => i.HasValue)
             .Select(i => i!.Value)
             .Sum(i => i.Weight * Weight(i.Name));
@@ -40,7 +46,7 @@ public sealed class Day07 : Day
         while (true)
         {
             node = start.Dequeue();
-            foreach (var (container, contained) in _rules)
+            foreach (var (container, contained) in _rules!)
                 if (contained.Any(i => i.HasValue && i.Value.Name == node) && p.Add(container))
                     start.Enqueue(container);
 
diff --git a/AOC2020/Day08.cs b/AOC2020/Day08.cs
index af0bd0d..a3ef2a6 100644
--- a/AOC2020/Day08.cs
+++ b/AOC2020/Day08.cs
@@ -5,12 +5,18 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day08 : Day
 {
-    private readonly (string instruction, int value)[] _instructions;
+    private (string instruction, int value)[]? _instructions;
     private int _accumulator;
     private int _currentInstruction;
 
-    public Day08() : base(2020, 8, "Handheld Halting") =>
+    public Day08() : base(2020, 8, "Handheld Halting")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _instructions = Input.Select(ParseLine).ToArray();
+    }
 
     private static (string, int) ParseLine(string line)
     {
@@ -22,7 +28,7 @@ public sealed class Day08 : Day
     {
         _accumulator = 0;
         _currentInstruction = 0;
-        var visited = new bool[_instructions.Length + 1];
+        var visited = new bool[_instructions!.Length + 1];
 
         while (!visited[_currentInstruction] && _currentInstruction < _instructions.Length)
         {
@@ -52,7 +58,7 @@ public sealed class Day08 : Day
 
     public override object Part2()
     {
-        for (var i = 0; i < _instructions.Length; i++)
+        for (var i = 0; i < _instructions!.Length; i++)
             // swap each nop and jmp and check if the program halts
             if (_instructions[i].instruction == "nop")
             {
diff --git a/AOC2020/Day09.cs b/AOC2020/Day09.cs
index 20a087d..4312a6f 100644
--- a/AOC2020/Day09.cs
+++ b/AOC2020/Day09.cs
@@ -5,22 +5,25 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day09 : Day
 {
-    private readonly long[] _list;
+    private long[]? _list;
     private long _part1;
 
-    public Day09() : base(2020, 9, "Encoding Error") =>
+    public Day09() : base(2020, 9, "Encoding Error")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _list = Input.Select(long.Parse).ToArray();
+    }
 
     public override object Part1()
     {
-        for (var i = 25; i < _list.Length - 25; i++)
+        for (var i = 25; i < _list!.Length - 25; i++)
         {
             var preamble = _list[(i - 25)..i];
             if (!preamble.Any(num1 => preamble.Any(num2 => num1 + num2 == _list[i])))
-            {
-                _part1 = _list[i];
-                return _part1;
-            }
+                return _part1 = _list[i];
         }
 
         return "";
@@ -28,7 +31,7 @@ public sealed class Day09 : Day
 
     public override object Part2()
     {
-        for (var i = 0; i < _list.Length; i++)
+        for (var i = 0; i < _list!.Length; i++)
         {
             long sum = 0;
             for (var j = i; j < _list.Length; j++)
diff --git a/AOC2020/Day10.cs b/AOC2020/Day10.cs
index e2b45fe..388e529 100644
--- a/AOC2020/Day10.cs
+++ b/AOC2020/Day10.cs
@@ -5,10 +5,14 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day10 : Day
 {
-    private readonly int[] _adapters;
-    private readonly long[] _memo;
+    private int[]? _adapters;
+    private long[]? _memo;
 
     public Day10() : base(2020, 10, "Adapter Array")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var parsed = Input.Select(int.Parse).ToArray();
         // add socket and device to the list
@@ -18,8 +22,8 @@ public sealed class Day10 : Day
 
     private long Connections(int i)
     {
-        if (i == _adapters.Length - 1) _memo[i] = 1;
-        if (_memo[i] > 0) return _memo[i];
+        if (i == _adapters!.Length - 1) _memo![i] = 1;
+        if (_memo![i] > 0) return _memo[i];
 
         for (var j = i + 1; j <= i + 3 && j < _adapters.Length; j++)
             if (_adapters[j] - _adapters[i] <= 3)
@@ -33,7 +37,7 @@ public sealed class Day10 : Day
         var ones = 0;
         var threes = 0;
 
-        for (var i = 0; i < _adapters.Length - 1; i++)
+        for (var i = 0; i < _adapters!.Length - 1; i++)
             switch (_adapters[i + 1] - _adapters[i])
             {
                 case 1:
@@ -49,4 +53,4 @@ public sealed class Day10 : Day
     }
 
     public override object Part2() => Connections(0);
-}
+}
\ No newline at end of file
diff --git a/AOC2020/Day11.cs b/AOC2020/Day11.cs
index 092d811..400727a 100644
--- a/AOC2020/Day11.cs
+++ b/AOC2020/Day11.cs
@@ -9,6 +9,10 @@ public sealed class Day11 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         var prev = new LifeGame(Input);
diff --git a/AOC2020/Day12.cs b/AOC2020/Day12.cs
index c7022e5..855c930 100644
--- a/AOC2020/Day12.cs
+++ b/AOC2020/Day12.cs
@@ -9,6 +9,10 @@ public sealed class Day12 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     private static void Swap(ref int x, ref int y) => (y, x) = (x, y);
 
     private (int x, int y, int sx, int sy) ProcessInstructions()
diff --git a/AOC2020/Day13.cs b/AOC2020/Day13.cs
index d883e3e..c5fb3da 100644
--- a/AOC2020/Day13.cs
+++ b/AOC2020/Day13.cs
@@ -5,11 +5,15 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day13 : Day
 {
-    private readonly long[] _buses;
-    private readonly long _earliest;
-    private readonly string[] _fullSchedule;
+    private long[]? _buses;
+    private long _earliest;
+    private string[]? _fullSchedule;
 
     public Day13() : base(2020, 13, "Shuttle Search")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _earliest = long.Parse(Input.First());
         _fullSchedule = Input.Last().Split(',');
@@ -19,9 +23,9 @@ public sealed class Day13 : Day
     public override object Part1()
     {
         for (var i = _earliest; ; i++)
-            if (_buses.Any(b => i % b == 0))
+            if (_buses!.Any(b => i % b == 0))
             {
-                var bus = _buses.First(b => i % b == 0);
+                var bus = _buses!.First(b => i % b == 0);
                 return bus * (i - _earliest);
             }
     }
@@ -31,7 +35,7 @@ public sealed class Day13 : Day
         var i = 0;
         long result = 1, multiplier = 1;
 
-        foreach (var id in _fullSchedule)
+        foreach (var id in _fullSchedule!)
         {
             if (id != "x")
             {
diff --git a/AOC2020/Day14.cs b/AOC2020/Day14.cs
index ee150c3..72dbe1c 100644
--- a/AOC2020/Day14.cs
+++ b/AOC2020/Day14.cs
@@ -9,6 +9,10 @@ public sealed class Day14 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         var writes = new Dictionary<ulong, ulong>();
diff --git a/AOC2020/Day15.cs b/AOC2020/Day15.cs
index bb29fec..e97b404 100644
--- a/AOC2020/Day15.cs
+++ b/AOC2020/Day15.cs
@@ -5,11 +5,15 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day15 : Day
 {
-    private readonly int[] _turns;
+    private int[]? _turns;
     private int _current;
     private int _i;
 
     public Day15() : base(2020, 15, "Rambunctious Recitation")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var initial = Input.First().Split(',').Select(int.Parse).ToArray();
         _turns = new int[30_000_000];
@@ -23,7 +27,7 @@ public sealed class Day15 : Day
     {
         for (; _i != 2020; _i++)
         {
-            var next = _turns[_current] > 0 ? _i - _turns[_current] : 0;
+            var next = _turns![_current] > 0 ? _i - _turns[_current] : 0;
             _turns[_current] = _i;
             _current = next;
         }
@@ -35,7 +39,7 @@ public sealed class Day15 : Day
     {
         for (; _i != 30_000_000; _i++)
         {
-            var next = _turns[_current] > 0 ? _i - _turns[_current] : 0;
+            var next = _turns![_current] > 0 ? _i - _turns[_current] : 0;
             _turns[_current] = _i;
             _current = next;
         }
diff --git a/AOC2020/Day16.cs b/AOC2020/Day16.cs
index a72db54..9af6052 100644
--- a/AOC2020/Day16.cs
+++ b/AOC2020/Day16.cs
@@ -5,10 +5,14 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day16 : Day
 {
-    private readonly Dictionary<string, List<Range>> _rules;
-    private readonly List<List<int>> _tickets;
+    private Dictionary<string, List<Range>>? _rules;
+    private List<List<int>>? _tickets;
 
     public Day16() : base(2020, 16, "Ticket Translation")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _tickets = new();
         _rules = new();
@@ -37,17 +41,17 @@ public sealed class Day16 : Day
 
     public override object Part1()
     {
-        var allValues = _tickets.Skip(1).SelectMany(t => t);
-        var allRules = _rules.Values.SelectMany(r => r);
+        var allValues = _tickets!.Skip(1).SelectMany(t => t);
+        var allRules = _rules!.Values.SelectMany(r => r);
         return allValues.Where(t => !allRules.Any(r => r.Contains(t))).Sum();
     }
 
     public override object Part2()
     {
-        var ticketFields = _tickets
+        var ticketFields = _tickets!
             // valid tickets
             .Where(ticket => ticket
-                .All(t => _rules.Values
+                .All(t => _rules!.Values
                     .SelectMany(r => r)
                     .Any(r => r.Contains(t))))
             // group by index
@@ -57,7 +61,7 @@ public sealed class Day16 : Day
             .Select((val, i) => new { Value = val, Index = i })
             .ToList();
 
-        var matchedRules = _rules
+        var matchedRules = _rules!
             // find matching rules and indices
             .SelectMany(x => ticketFields
                 .Where(y => y.Value.All(z => x.Value.Any(r => r.Contains(z))))
@@ -79,6 +83,6 @@ public sealed class Day16 : Day
 
         var departureFields = matchedRules.Where(r => r.Key.StartsWith("departure"));
 
-        return departureFields.Aggregate(1L, (l, match) => l * _tickets.First()[match.Index]);
+        return departureFields.Aggregate(1L, (l, match) => l * _tickets!.First()[match.Index]);
     }
 }
diff --git a/AOC2020/Day17.cs b/AOC2020/Day17.cs
index aac0284..424c330 100644
--- a/AOC2020/Day17.cs
+++ b/AOC2020/Day17.cs
@@ -8,8 +8,11 @@ public sealed class Day17 : Day
     private readonly Dictionary<(int x, int y, int z), char> _plane = new();
     private readonly Dictionary<(int x, int y, int z, int w), char> _plane4 = new();
 
-
     public Day17() : base(2020, 17, "Conway Cubes")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var input = Input.ToList();
 
@@ -107,14 +110,12 @@ public sealed class Day17 : Day
     public override object Part1()
     {
         var plane = Enumerable.Range(0, 6).Aggregate(_plane, (current, _) => Iterate(current));
-
         return plane.Values.Count(v => v == '#');
     }
 
     public override object Part2()
     {
         var plane = Enumerable.Range(0, 6).Aggregate(_plane4, (current, _) => Iterate4(current));
-
         return plane.Values.Count(v => v == '#');
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2020/Day18.cs b/AOC2020/Day18.cs
index cefb4ea..f97291c 100644
--- a/AOC2020/Day18.cs
+++ b/AOC2020/Day18.cs
@@ -5,10 +5,16 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day18 : Day
 {
-    private readonly List<string> _expressions;
+    private List<string>? _expressions;
 
-    public Day18() : base(2020, 18, "Operation Order") =>
+    public Day18() : base(2020, 18, "Operation Order")
+    {
+    }
+
+    public override void ProcessInput()
+    {
         _expressions = Input.Select(line => line.Replace(" ", "")).ToList();
+    }
 
     private static long Calculate(string expr, Func<char, int> precedence)
     {
@@ -62,8 +68,8 @@ public sealed class Day18 : Day
     }
 
     public override object Part1() =>
-        _expressions.Sum(expr => Calculate(expr, c => c == '+' || c == '*' ? 1 : 0));
+        _expressions!.Sum(expr => Calculate(expr, c => c is '+' or '*' ? 1 : 0));
 
     public override object Part2() =>
-        _expressions.Sum(expr => Calculate(expr, c => c switch { '+' => 2, '*' => 1, _ => 0 }));
+        _expressions!.Sum(expr => Calculate(expr, c => c switch { '+' => 2, '*' => 1, _ => 0 }));
 }
diff --git a/AOC2020/Day19.cs b/AOC2020/Day19.cs
index af43fdd..8d3d35b 100644
--- a/AOC2020/Day19.cs
+++ b/AOC2020/Day19.cs
@@ -5,11 +5,15 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day19 : Day
 {
-    private readonly string[] _messages;
-    private readonly Dictionary<string, string[][]> _rules;
-    private readonly Stack<string> _stack;
+    private string[]? _messages;
+    private Dictionary<string, string[][]>? _rules;
+    private Stack<string>? _stack;
 
     public Day19() : base(2020, 19, "Monster Messages")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _rules = Input.TakeWhile(l => !string.IsNullOrWhiteSpace(l))
             .Select(l => l.Split(':'))
@@ -24,10 +28,10 @@ public sealed class Day19 : Day
 
     private string MakeRegexExpression(string key)
     {
-        if (_stack.Count(s => s == key) > 10) return "x";
-        _stack.Push(key);
+        if (_stack!.Count(s => s == key) > 10) return "x";
+        _stack!.Push(key);
 
-        var sub = string.Join("|", _rules[key].Select(test => test.Length switch
+        var sub = string.Join("|", _rules![key].Select(test => test.Length switch
         {
             1 => test[0][0] == '"' ? test[0].Trim('"') : MakeRegexExpression(test[0]),
             _ => string.Join(string.Empty, test.Select(MakeRegexExpression))
@@ -39,15 +43,15 @@ public sealed class Day19 : Day
     public override object Part1()
     {
         var exp = new Regex($"^{MakeRegexExpression("0")}$");
-        return _messages.Count(m => exp.IsMatch(m));
+        return _messages!.Count(m => exp.IsMatch(m));
     }
 
     public override object Part2()
     {
         // fix rules 8 and 11
-        _rules["8"] = new[] { new[] { "42" }, new[] { "42", "8" } };
+        _rules!["8"] = new[] { new[] { "42" }, new[] { "42", "8" } };
         _rules["11"] = new[] { new[] { "42", "31" }, new[] { "42", "11", "31" } };
         var exp = new Regex($"^{MakeRegexExpression("0")}$");
-        return _messages.Count(m => exp.IsMatch(m));
+        return _messages!.Count(m => exp.IsMatch(m));
     }
 }
diff --git a/AOC2020/Day20.cs b/AOC2020/Day20.cs
index 2e6030e..2ea680d 100644
--- a/AOC2020/Day20.cs
+++ b/AOC2020/Day20.cs
@@ -9,6 +9,10 @@ public sealed class Day20 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         var puzzlePieces = ParsePiecesFromInput(Input.ToArray());
diff --git a/AOC2020/Day21.cs b/AOC2020/Day21.cs
index 9c26a51..71df5ae 100644
--- a/AOC2020/Day21.cs
+++ b/AOC2020/Day21.cs
@@ -5,10 +5,14 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day21 : Day
 {
-    private readonly IEnumerable<(string[] Allergens, string[] Ingredients)> _parsedFoods;
-    private readonly IEnumerable<(string Allergen, string Ingredient)> _dangerousFoods;
+    private IEnumerable<(string[] Allergens, string[] Ingredients)>? _parsedFoods;
+    private IEnumerable<(string Allergen, string Ingredient)>? _dangerousFoods;
 
     public Day21() : base(2020, 21, "Allergen Assessment")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _parsedFoods = Input.Select(line => line.TrimEnd(')').Split(" (contains "))
             .Select(split => (Allergens: split[1].Split(", "), Ingredients: split[0].Split(' ')));
@@ -34,12 +38,12 @@ public sealed class Day21 : Day
     }
 
     public override object Part1() =>
-        _parsedFoods
+        _parsedFoods!
             .SelectMany(i => i.Ingredients)
-            .Count(i => !_dangerousFoods.Select(t => t.Ingredient).Contains(i));
+            .Count(i => !_dangerousFoods!.Select(t => t.Ingredient).Contains(i));
 
     public override object Part2() =>
-        string.Join(',', _dangerousFoods
+        string.Join(',', _dangerousFoods!
             .OrderBy(i => i.Allergen)
             .Select(i => i.Ingredient));
 }
diff --git a/AOC2020/Day22.cs b/AOC2020/Day22.cs
index f0558b6..899366f 100644
--- a/AOC2020/Day22.cs
+++ b/AOC2020/Day22.cs
@@ -9,6 +9,10 @@ public sealed class Day22 : Day
     private readonly Queue<int> _deck2 = new();
 
     public Day22() : base(2020, 22, "Crab Combat")
+    {
+    }
+
+    public override void ProcessInput()
     {
         Reset();
     }
@@ -82,7 +86,8 @@ public sealed class Day22 : Day
         return (deck1, deck2);
     }
 
-    private (Queue<int> deck1, Queue<int> deck2) Play(IEnumerable<int> enumerable1, IEnumerable<int> enumerable2, bool recursive) =>
+    private (Queue<int> deck1, Queue<int> deck2) Play(IEnumerable<int> enumerable1, IEnumerable<int> enumerable2,
+        bool recursive) =>
         Play(new(enumerable1), new(enumerable2), recursive);
 
     private static int CalculateScore(IReadOnlyCollection<int> deck) =>
diff --git a/AOC2020/Day23.cs b/AOC2020/Day23.cs
index 24c119b..dd77865 100644
--- a/AOC2020/Day23.cs
+++ b/AOC2020/Day23.cs
@@ -6,11 +6,15 @@ namespace AOC2020;
 public sealed class Day23 : Day
 {
     private readonly Dictionary<long, long> _cups = new();
-    private readonly ImmutableList<long> _initialCups;
-    private readonly long[] _move;
+    private ImmutableList<long>? _initialCups;
+    private long[]? _move;
     private long _current;
 
     public Day23() : base(2020, 23, "Crab Cups")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _initialCups = Input.First().Select(c => long.Parse(c.ToString())).ToImmutableList();
         _current = _initialCups.First();
@@ -31,10 +35,10 @@ public sealed class Day23 : Day
                 _cups.Remove(id);
                 _cups[_current] = removedNext;
 
-                _move[i] = id;
+                _move![i] = id;
             }
 
-            while (_move.Contains(dest))
+            while (_move!.Contains(dest))
             {
                 dest--;
                 if (dest == 0) dest = _cups.Count + 3;
@@ -43,7 +47,7 @@ public sealed class Day23 : Day
             for (var i = 0; i <= 2; i++)
             {
                 var id = _cups[dest];
-                _cups[dest] = _move[i];
+                _cups[dest] = _move![i];
                 _cups.Add(_move[i], id);
                 dest = _cups[dest];
             }
@@ -54,7 +58,7 @@ public sealed class Day23 : Day
 
     public override object Part1()
     {
-        for (var i = 0; i < _initialCups.Count; i++)
+        for (var i = 0; i < _initialCups!.Count; i++)
             _cups[_initialCups[i]] = _initialCups[(i + 1) % _initialCups.Count];
 
         DoMoves(100);
@@ -73,7 +77,7 @@ public sealed class Day23 : Day
     public override object Part2()
     {
         _cups.Clear();
-        for (var i = 0; i < _initialCups.Count; i++)
+        for (var i = 0; i < _initialCups!.Count; i++)
             _cups[_initialCups[i]] = _initialCups[(i + 1) % _initialCups.Count];
 
         // add a million cups
diff --git a/AOC2020/Day24.cs b/AOC2020/Day24.cs
index 8b094e2..ffed954 100644
--- a/AOC2020/Day24.cs
+++ b/AOC2020/Day24.cs
@@ -7,17 +7,21 @@ public sealed class Day24 : Day
 {
     private static readonly Dictionary<string, (int q, int r, int s)> Directions = new()
     {
-        { "e", (1, 0, -1) },
-        { "w", (-1, 0, 1) },
+        { "e",  (1, 0, -1) },
+        { "w",  (-1, 0, 1) },
         { "se", (0, 1, -1) },
         { "sw", (-1, 1, 0) },
         { "nw", (0, -1, 1) },
         { "ne", (1, -1, 0) }
     };
 
-    private Dictionary<(int q, int r, int s), Tile> _tiles;
+    private Dictionary<(int q, int r, int s), Tile>? _tiles;
 
     public Day24() : base(2020, 24, "Lobby Layout")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _tiles = Input
             .Select(Tile.FromLine)
@@ -27,27 +31,27 @@ public sealed class Day24 : Day
             .ToDictionary(t => t.Location);
     }
 
-    public override object Part1() => _tiles.Count;
+    public override object Part1() => _tiles!.Count;
 
     public override object Part2()
     {
         foreach (var _ in Enumerable.Range(0, 100))
         {
-            _tiles = _tiles
+            _tiles = _tiles!
                 .SelectMany(t => Directions.Select(d => t.Value + d.Value))
                 .Distinct()
                 .Where(t =>
                 {
                     var neighborCount = Directions
                         .Select(d => t + d.Value)
-                        .Count(neighbor => _tiles.ContainsKey(neighbor.Location));
+                        .Count(neighbor => _tiles!.ContainsKey(neighbor.Location));
 
-                    return neighborCount == 2 || _tiles.ContainsKey(t.Location) && neighborCount == 1;
+                    return neighborCount == 2 || _tiles!.ContainsKey(t.Location) && neighborCount == 1;
                 })
                 .ToDictionary(t => t.Location);
         }
 
-        return _tiles.Count;
+        return _tiles!.Count;
     }
 
     private record Tile
diff --git a/AOC2020/Day25.cs b/AOC2020/Day25.cs
index af0167d..7ff1751 100644
--- a/AOC2020/Day25.cs
+++ b/AOC2020/Day25.cs
@@ -9,6 +9,10 @@ public sealed class Day25 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         var cardKey = int.Parse(Input.First());
diff --git a/AOC2021/Day01.cs b/AOC2021/Day01.cs
index 7c89fb7..411bb88 100644
--- a/AOC2021/Day01.cs
+++ b/AOC2021/Day01.cs
@@ -5,16 +5,20 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day01 : Day
 {
-    private readonly List<int> _readings;
-    
+    private List<int>? _readings;
+
     public Day01() : base(2021, 1, "Sonar Sweep")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _readings = Input.Select(int.Parse).ToList();
     }
 
     public override object Part1() =>
-        Enumerable.Range(0, _readings.Count - 1).Count(i => _readings[i + 1] > _readings[i]);
+        Enumerable.Range(0, _readings!.Count - 1).Count(i => _readings[i + 1] > _readings[i]);
 
     public override object Part2() =>
-        Enumerable.Range(0, _readings.Count - 3).Count(i => _readings[i + 3] > _readings[i]);
+        Enumerable.Range(0, _readings!.Count - 3).Count(i => _readings[i + 3] > _readings[i]);
 }
diff --git a/AOC2021/Day02.cs b/AOC2021/Day02.cs
index 81f02b0..3627262 100644
--- a/AOC2021/Day02.cs
+++ b/AOC2021/Day02.cs
@@ -9,6 +9,10 @@ public sealed class Day02 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     public override object Part1()
     {
         int horiz = 0, depth = 0;
diff --git a/AOC2021/Day03.cs b/AOC2021/Day03.cs
index 9122acc..a5a6cdb 100644
--- a/AOC2021/Day03.cs
+++ b/AOC2021/Day03.cs
@@ -5,16 +5,20 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day03 : Day
 {
-    private readonly List<string> _report;
-    
+    private List<string>? _report;
+
     public Day03() : base(2021, 3, "Binary Diagnostic")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _report = Input.ToList();
     }
 
     public override object Part1()
     {
-        var l = _report.Count / 2;
+        var l = _report!.Count / 2;
         var g = new StringBuilder();
         var e = new StringBuilder();
         
@@ -33,8 +37,8 @@ public sealed class Day03 : Day
 
     public override object Part2()
     {
-        var o = _report;
-        var c = _report;
+        var o = _report!;
+        var c = _report!;
 
         char MostCommon(int i, IReadOnlyCollection<string> report) =>
             report.Count(r => r[i] == '1') >= report.Count / 2.0 ? '1' : '0';
diff --git a/AOC2021/Day04.cs b/AOC2021/Day04.cs
index d993431..4e969e7 100644
--- a/AOC2021/Day04.cs
+++ b/AOC2021/Day04.cs
@@ -5,11 +5,15 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day04 : Day
 {
-    private readonly List<int> _call;
-    private readonly List<List<int>> _boards;
-    private readonly int _size;
-    
+    private List<int>? _call;
+    private List<List<int>>? _boards;
+    private int _size;
+
     public Day04() : base(2021, 4, "Giant Squid")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _call = Input.First().Split(',').Select(int.Parse).ToList();
         _boards = new();
@@ -41,34 +45,34 @@ public sealed class Day04 : Day
             b = FirstWin(i);
         }
 
-        var called = _call.Take(i).ToHashSet();
-        return called.Last() * _boards[b].Where(x => !called.Contains(x)).Sum();
+        var called = _call!.Take(i).ToHashSet();
+        return called.Last() * _boards![b].Where(x => !called.Contains(x)).Sum();
     }
 
     public override object Part2()
     {
         Dictionary<int, bool> wonBoards = new();
-        for (var i = 0; i < _boards.Count; i++)
+        for (var i = 0; i < _boards!.Count; i++)
             wonBoards[i] = false;
 
         var j = _size;
         while (wonBoards.Values.Count(b => b) != wonBoards.Count - 1)
         {
-            var c = _call.Take(j).ToHashSet();
+            var c = _call!.Take(j).ToHashSet();
             for (var u = 0; u < _boards.Count; u++)
                 wonBoards[u] = HasWin(c, _boards[u]);
             j++;
         }
 
-        var called = _call.Take(j).ToHashSet();
+        var called = _call!.Take(j).ToHashSet();
         var b = wonBoards.Single(kvp => !kvp.Value).Key;
         return called.Last() * _boards[b].Where(x => !called.Contains(x)).Sum();
     }
 
     private int FirstWin(int i)
     {
-        var c = _call.Take(i).ToHashSet();
-        for (var j = 0; j < _boards.Count; j++)
+        var c = _call!.Take(i).ToHashSet();
+        for (var j = 0; j < _boards!.Count; j++)
             if (HasWin(c, _boards[j])) return j;
         return -1;
     }
diff --git a/AOC2021/Day05.cs b/AOC2021/Day05.cs
index 2823a00..fc180dd 100644
--- a/AOC2021/Day05.cs
+++ b/AOC2021/Day05.cs
@@ -3,15 +3,19 @@ namespace AOC2021;
 /// <summary>
 /// Day 5: <a href="https://adventofcode.com/2021/day/5"/>
 /// </summary>
-public sealed class Day05 : Day
+public sealed partial class Day05 : Day
 {
     public Day05() : base(2021, 5, "Hydrothermal Venture")
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     private int Solve(bool diagonals = false) =>
         Input
-            .Select(s => Regex.Split(s, @"\D+").Select(int.Parse).ToList())
+            .Select(s => NonDigits().Split(s).Select(int.Parse).ToList())
             .Where(t => diagonals || t[0] == t[2] || t[1] == t[3])
             .SelectMany(t =>
                 Enumerable.Range(0, Math.Max(Math.Abs(t[0] - t[2]), Math.Abs(t[1] - t[3])) + 1)
@@ -24,4 +28,7 @@ public sealed class Day05 : Day
     public override object Part1() => Solve();
 
     public override object Part2() => Solve(diagonals: true);
+
+    [GeneratedRegex(@"\D+")]
+    private static partial Regex NonDigits();
 }
diff --git a/AOC2021/Day06.cs b/AOC2021/Day06.cs
index 0f470f4..287df2c 100644
--- a/AOC2021/Day06.cs
+++ b/AOC2021/Day06.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day06 : Day
 {
-    private readonly long _p1, _p2;
+    private long _p1, _p2;
 
     public Day06() : base(2021, 6, "Lanternfish")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var fishes = Input.First().Split(',').Select(long.Parse).ToList();
         Dictionary<long, long> counts = new();
diff --git a/AOC2021/Day07.cs b/AOC2021/Day07.cs
index aafeabb..a488411 100644
--- a/AOC2021/Day07.cs
+++ b/AOC2021/Day07.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day07 : Day
 {
-    private readonly List<long> _tape;
-    
+    private List<long>? _tape;
+
     public Day07() : base(2021, 7, "The Treachery of Whales")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _tape = Input.First().Split(',').Select(long.Parse).OrderBy(i => i).ToList();
     }
@@ -16,13 +20,13 @@ public sealed class Day07 : Day
 
     public override object Part1()
     {
-        var i = _tape[_tape.Count / 2];
+        var i = _tape![_tape.Count / 2];
         return _tape.Select(t => Math.Abs(t - i)).Sum();
     }
 
     public override object Part2()
     {
-        var avg = (decimal)_tape.Sum() / _tape.Count;
+        var avg = (decimal)_tape!.Sum() / _tape!.Count;
         var floor = _tape.Select(t => ArithmeticSumTo(Math.Abs(t - (long)Math.Floor(avg)))).Sum();
         var ceil  = _tape.Select(t => ArithmeticSumTo(Math.Abs(t - (long)Math.Ceiling(avg)))).Sum();
         return Math.Min(floor, ceil);
diff --git a/AOC2021/Day08.cs b/AOC2021/Day08.cs
index f3684c9..cec396f 100644
--- a/AOC2021/Day08.cs
+++ b/AOC2021/Day08.cs
@@ -12,6 +12,10 @@ public sealed class Day08 : Day
     {
     }
 
+    public override void ProcessInput()
+    {
+    }
+
     private static int MatchDigit(string lit) =>
         lit switch
         {
diff --git a/AOC2021/Day09.cs b/AOC2021/Day09.cs
index 13bd668..b471958 100644
--- a/AOC2021/Day09.cs
+++ b/AOC2021/Day09.cs
@@ -7,11 +7,15 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day09 : Day
 {
-    private readonly int _part1Sum;
-    private readonly List<(int x, int y)> _lowPoints;
-    private readonly List<string> _map;
+    private int _part1Sum;
+    private List<(int x, int y)>? _lowPoints;
+    private List<string>? _map;
 
     public Day09() : base(2021, 9, "Smoke Basin")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _part1Sum = 0;
         _lowPoints = new();
@@ -36,7 +40,7 @@ public sealed class Day09 : Day
     public override object Part2()
     {
         var sizes = new List<long>();
-        foreach (var (x, y) in _lowPoints)
+        foreach (var (x, y) in _lowPoints!)
         {
             var s = 0;
             var seen = new HashSet<(int x, int y)>();
@@ -44,11 +48,11 @@ public sealed class Day09 : Day
             IEnumerable<(int x, int y)> Traverse((int x, int y) p)
             {
                 var (i, j) = p;
-                if (_map[j][i] == '9') yield break;
+                if (_map![j][i] == '9') yield break;
                 if (seen.Contains((i, j))) yield break;
                 seen.Add((i, j));
                 s++;
-                
+
                 if (j > 0)
                     yield return (i, j - 1);
                 if (j < _map.Count - 1)
@@ -68,4 +72,4 @@ public sealed class Day09 : Day
             .Take(3)
             .Aggregate(1L, (a, b) => a * b);
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2021/Day10.cs b/AOC2021/Day10.cs
index 0b94417..76f6ca2 100644
--- a/AOC2021/Day10.cs
+++ b/AOC2021/Day10.cs
@@ -29,10 +29,15 @@ public sealed class Day10 : Day
         { '<', 4 }
     };
 
-    private readonly long _score1;
     private readonly List<long> _scores2 = new();
 
+    private long _score1;
+
     public Day10() : base(2021, 10, "Syntax Scoring")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _score1 = 0L;
         foreach (var line in Input)
diff --git a/AOC2021/Day11.cs b/AOC2021/Day11.cs
index e99483c..76fbcae 100644
--- a/AOC2021/Day11.cs
+++ b/AOC2021/Day11.cs
@@ -5,11 +5,14 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day11 : Day
 {
-    private int _flashTally;
-    private readonly int _flashesAfter100, _totalTurns;
-    private readonly int[][] _octopusField;
-    
+    private int _flashTally, _flashesAfter100, _totalTurns;
+    private int[][]? _octopusField;
+
     public Day11() : base(2021, 11, "Dumbo Octopus")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _octopusField = Input.Select(line => line.Select(c => int.Parse($"{c}")).ToArray()).ToArray();
 
@@ -44,7 +47,7 @@ public sealed class Day11 : Day
     private void FlashAt(int r, int c)
     {
         _flashTally++;
-        _octopusField[r][c] = -1;
+        _octopusField![r][c] = -1;
         foreach (var rr in new[] { -1, 0, 1 }.Select(dr => dr + r))
         foreach (var cc in new[] { -1, 0, 1 }.Select(dc => dc + c))
             if (0 <= rr && rr < _octopusField.Length && 0 <= cc && cc < _octopusField[0].Length && _octopusField[rr][cc] != -1)
diff --git a/AOC2021/Day12.cs b/AOC2021/Day12.cs
index d956f38..740ca65 100644
--- a/AOC2021/Day12.cs
+++ b/AOC2021/Day12.cs
@@ -8,6 +8,10 @@ public sealed class Day12 : Day
     private readonly Dictionary<string, List<string>> _edges = new();
 
     public Day12() : base(2021, 12, "Passage Pathing")
+    {
+    }
+
+    public override void ProcessInput()
     {
         foreach (var line in Input)
         {
diff --git a/AOC2021/Day13.cs b/AOC2021/Day13.cs
index 6f2cde0..0b063a8 100644
--- a/AOC2021/Day13.cs
+++ b/AOC2021/Day13.cs
@@ -7,10 +7,14 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day13 : Day
 {
-    private List<(int x, int y)> _dots;
-    private readonly List<(char axis, int index)> _folds;
-    
+    private List<(int x, int y)>? _dots;
+    private List<(char axis, int index)>? _folds;
+
     public Day13() : base(2021, 13, "Transparent Origami")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var s = Input.Split("").ToList();
         
@@ -47,14 +51,14 @@ public sealed class Day13 : Day
 
     private string PrintGrid()
     {
-        var xMax = _dots.Max(g => g.x);
-        var yMax = _dots.Max(g => g.y);
+        var xMax = _dots!.Max(g => g.x);
+        var yMax = _dots!.Max(g => g.y);
         var s = new StringBuilder();
 
         for (var y = 0; y <= yMax; y++)
         {
             for (var x = 0; x <= xMax; x++)
-                s.Append(_dots.Contains((x, y)) ? "█" : "▒");
+                s.Append(_dots!.Contains((x, y)) ? "█" : "▒");
 
             if (y < yMax) s.AppendLine();
         }
@@ -63,12 +67,12 @@ public sealed class Day13 : Day
     }
 
     public override object Part1() =>
-        DoFold(_dots, _folds[0].axis, _folds[0].index).Count;
+        DoFold(_dots!, _folds![0].axis, _folds[0].index).Count;
 
     public override object Part2()
     {
-        foreach (var (axis, at) in _folds)
-            _dots = DoFold(_dots, axis, at);
+        foreach (var (axis, at) in _folds!)
+            _dots = DoFold(_dots!, axis, at);
 
         return PrintGrid();
     }
diff --git a/AOC2021/Day14.cs b/AOC2021/Day14.cs
index ffb7f04..b4fbebc 100644
--- a/AOC2021/Day14.cs
+++ b/AOC2021/Day14.cs
@@ -5,10 +5,14 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day14 : Day
 {
-    private readonly string _template;
-    private readonly Dictionary<string, string> _substitutionPairs;
+    private string? _template;
+    private Dictionary<string, string>? _substitutionPairs;
 
     public Day14() : base(2021, 14, "Extended Polymerization")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _template = Input.First();
         _substitutionPairs = Input.Skip(2).Select(l => l.Split(" -> ")).ToDictionary(k => k[0], v => v[1]);
@@ -21,7 +25,7 @@ public sealed class Day14 : Day
         for (var i = 0; i < input.Length - 1; i++)
         {
             var k = input.Substring(i, 2);
-            if (_substitutionPairs.ContainsKey(k))
+            if (_substitutionPairs!.ContainsKey(k))
             {
                 result.Append(k[0]);
                 result.Append(_substitutionPairs[k]);
@@ -40,7 +44,7 @@ public sealed class Day14 : Day
     private long Solve(int steps)
     {
         var moleculeCounts = new Dictionary<string, long>();
-        foreach (var i in Enumerable.Range(0, _template.Length - 1))
+        foreach (var i in Enumerable.Range(0, _template!.Length - 1))
         {
             var k = _template.Substring(i, 2);
             moleculeCounts[k] = moleculeCounts.GetValueOrDefault(k) + 1;
@@ -51,7 +55,7 @@ public sealed class Day14 : Day
             var updated = new Dictionary<string, long>();
             foreach (var (molecule, count) in moleculeCounts)
             {
-                var (a, n, b) = (molecule[0], _substitutionPairs[molecule], molecule[1]);
+                var (a, n, b) = (molecule[0], _substitutionPairs![molecule], molecule[1]);
                 updated[$"{a}{n}"] = updated.GetValueOrDefault($"{a}{n}") + count;
                 updated[$"{n}{b}"] = updated.GetValueOrDefault($"{n}{b}") + count;
             }
@@ -74,9 +78,9 @@ public sealed class Day14 : Day
 
     public override object Part1()
     {
-        var s = Enumerable.Range(0, 10).Aggregate(_template, (current, _) => DoStep(current));
+        var s = Enumerable.Range(0, 10).Aggregate(_template, (current, _) => DoStep(current!));
 
-        var most = s.ToCharArray()
+        var most = s!.ToCharArray()
             .GroupBy(c => c)
             .OrderByDescending(g => g.Count())
             .Select(g => g.Count())
diff --git a/AOC2021/Day15.cs b/AOC2021/Day15.cs
index 91924f1..7a6afa4 100644
--- a/AOC2021/Day15.cs
+++ b/AOC2021/Day15.cs
@@ -15,11 +15,15 @@ public record Node
 public sealed class Day15 : Day
 {
     private static readonly (int x, int y)[] Adjacent = { (-1, 0), (1, 0), (0, -1), (0, 1) };
-    private readonly Dictionary<(int x, int y), Node> _fullGrid;
-    private readonly Dictionary<(int x, int y), Node> _grid;
-    private readonly int _width;
+    private Dictionary<(int x, int y), Node>? _fullGrid;
+    private Dictionary<(int x, int y), Node>? _grid;
+    private int _width;
 
     public Day15() : base(2021, 15, "Chiton")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _grid = Input
             .SelectMany((line, y) =>
@@ -76,8 +80,8 @@ public sealed class Day15 : Day
     }
 
     public override object Part1() =>
-        DijkstraCost(_grid, _grid[(_width - 1, _width - 1)]);
+        DijkstraCost(_grid!, _grid![(_width - 1, _width - 1)]);
 
     public override object Part2() =>
-        DijkstraCost(_fullGrid, _fullGrid[(5 * _width - 1, 5 * _width - 1)]);
+        DijkstraCost(_fullGrid!, _fullGrid![(5 * _width - 1, 5 * _width - 1)]);
 }
diff --git a/AOC2021/Day16.cs b/AOC2021/Day16.cs
index d26d47d..dc77ba3 100644
--- a/AOC2021/Day16.cs
+++ b/AOC2021/Day16.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day16 : Day
 {
-    private readonly Packet _packet;
+    private Packet? _packet;
 
     public Day16() : base(2021, 16, "Packet Decoder")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var bits = string.Join(string.Empty,
             Input.First().Select(c => Convert.ToString(Convert.ToInt32(c.ToString(), 16), 2).PadLeft(4, '0')));
@@ -81,7 +85,7 @@ public sealed class Day16 : Day
             };
     }
 
-    public override object Part1() => _packet.VersionTotal;
+    public override object Part1() => _packet!.VersionTotal;
 
-    public override object Part2() => _packet.Eval;
+    public override object Part2() => _packet!.Eval;
 }
diff --git a/AOC2021/Day17.cs b/AOC2021/Day17.cs
index b5a1409..64142bb 100644
--- a/AOC2021/Day17.cs
+++ b/AOC2021/Day17.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day17 : Day
 {
-    private readonly List<int> _target;
+    private List<int>? _target;
 
     public Day17() : base(2021, 17, "Trick Shot")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _target = Input.First()
             .Split(' ', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)
@@ -20,7 +24,7 @@ public sealed class Day17 : Day
 
     public override object Part1()
     {
-        var initialYVelocity = Math.Abs(_target[2]) - 1;
+        var initialYVelocity = Math.Abs(_target![2]) - 1;
         return (initialYVelocity + 1) * initialYVelocity / 2;
     }
 
@@ -28,7 +32,7 @@ public sealed class Day17 : Day
     {
         var successfulVelocities = new HashSet<(int x, int y)>();
         var xMin = 1;
-        while (xMin * (xMin + 1) / 2 < _target[0]) xMin++;
+        while (xMin * (xMin + 1) / 2 < _target![0]) xMin++;
 
         for (var x = xMin; x <= _target[1]; x++)
         for (var y = _target[2]; y < Math.Abs(_target[2]); y++)
diff --git a/AOC2021/Day18.cs b/AOC2021/Day18.cs
index 30fc17f..f22cb73 100644
--- a/AOC2021/Day18.cs
+++ b/AOC2021/Day18.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day18 : Day
 {
-    private readonly List<string> _fishes;
+    private List<string>? _fishes;
 
     public Day18() : base(2021, 18, "Snailfish")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _fishes = Input.ToList();
     }
@@ -106,12 +110,12 @@ public sealed class Day18 : Day
     }
 
     public override object Part1() =>
-        Magnitude(_fishes.Skip(1).Aggregate(Parse(_fishes.First()), (a, b) => Add(a, Parse(b))).Root);
+        Magnitude(_fishes!.Skip(1).Aggregate(Parse(_fishes!.First()), (a, b) => Add(a, Parse(b))).Root);
 
     public override object Part2()
     {
         var best = 0L;
-        for (var i = 0; i < _fishes.Count; i++)
+        for (var i = 0; i < _fishes!.Count; i++)
             best = _fishes
                 .Where((_, j) => i != j)
                 .Select(t => Add(Parse(_fishes[i]), Parse(t)))
diff --git a/AOC2021/Day19.cs b/AOC2021/Day19.cs
index 30c5342..fe3e57f 100644
--- a/AOC2021/Day19.cs
+++ b/AOC2021/Day19.cs
@@ -8,10 +8,14 @@ public sealed class Day19 : Day
     private static readonly (int, int, int)[] Axes =
         { (0, 1, 0), (0, -1, 0), (1, 0, 0), (-1, 0, 0), (0, 0, 1), (0, 0, -1) };
 
-    private readonly List<HashSet<Vector3>> _scans;
+    private List<HashSet<Vector3>>? _scans;
     private List<HashSet<Vector3>> _scanners = new();
 
     public Day19() : base(2021, 19, "Beacon Scanner")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _scans = Input
             .Aggregate(new List<HashSet<Vector3>>(), (list, line) =>
@@ -126,7 +130,7 @@ public sealed class Day19 : Day
 
     public override object Part1()
     {
-        var scans = _scans;
+        var scans = _scans!;
         _scanners = scans.Select(_ => new HashSet<Vector3> { (0, 0, 0) }).ToList();
         while (scans.Count > 1)
             (scans, _scanners) = Reduce(scans, _scanners);
diff --git a/AOC2021/Day20.cs b/AOC2021/Day20.cs
index 597f9ad..99b4ff5 100644
--- a/AOC2021/Day20.cs
+++ b/AOC2021/Day20.cs
@@ -5,10 +5,14 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day20 : Day
 {
-    private readonly ImmutableArray<bool> _enhancementAlgorithm;
-    private readonly Image _initialImage;
+    private ImmutableArray<bool> _enhancementAlgorithm;
+    private Image? _initialImage;
 
     public Day20() : base(2021, 20, "Trench Map")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _enhancementAlgorithm = Input.First().Select(ch => ch == '#').ToImmutableArray();
         _initialImage = Parse(Input.Skip(2).ToList());
@@ -45,10 +49,10 @@ public sealed class Day20 : Day
     }
 
     public override object Part1() =>
-        Enhance(_initialImage, 2).PixelCount;
+        Enhance(_initialImage!, 2).PixelCount;
 
     public override object Part2() =>
-        Enhance(_initialImage, 50).PixelCount;
+        Enhance(_initialImage!, 50).PixelCount;
 
     private record struct Point(int X, int Y);
 
@@ -66,6 +70,7 @@ public sealed class Day20 : Day
     {
         private bool this[Point pt] =>
             Bounds.Contains(pt) ? Pixels.Contains(pt) : InfiniteValue;
+
         public int PixelCount => Pixels.Count(Bounds.Contains);
 
         public int GetEnhanceInput(Point pt)
@@ -78,4 +83,4 @@ public sealed class Day20 : Day
             return values.Aggregate(0, (p, n) => (p << 1) | n);
         }
     }
-}
+}
\ No newline at end of file
diff --git a/AOC2021/Day21.cs b/AOC2021/Day21.cs
index 6bf4846..6e0cd0a 100644
--- a/AOC2021/Day21.cs
+++ b/AOC2021/Day21.cs
@@ -5,13 +5,17 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day21 : Day
 {
-    private readonly int _player1, _player2;
+    private int _player1, _player2;
     private readonly Dictionary<int, ulong> _possibleRollOutComes = new();
     private int _deterministicDie = 1;
     private int _rollCount;
     private ulong _player1Victories, _player2Victories;
 
     public Day21() : base(2021, 21, "Dirac Dice")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var s = Input
             .Select(l => l.Split(": ")[1])
diff --git a/AOC2021/Day22.cs b/AOC2021/Day22.cs
index 3058b32..d206d8e 100644
--- a/AOC2021/Day22.cs
+++ b/AOC2021/Day22.cs
@@ -6,8 +6,12 @@ namespace AOC2021;
 public sealed class Day22 : Day
 {
     private readonly List<Instruction> _instructions = new();
-    
+
     public Day22() : base(2021, 22, "Reactor Reboot")
+    {
+    }
+
+    public override void ProcessInput()
     {
         foreach (var line in Input)
         {
diff --git a/AOC2021/Day23.cs b/AOC2021/Day23.cs
index 250f8db..f57e177 100644
--- a/AOC2021/Day23.cs
+++ b/AOC2021/Day23.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day23 : Day
 {
-    private readonly List<char> _crabs;
+    private List<char>? _crabs;
 
     public Day23() : base(2021, 23, "Amphipod")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _crabs = Input.SelectMany(l => l).Where(char.IsLetter).ToList();
     }
@@ -83,7 +87,7 @@ public sealed class Day23 : Day
     public override object Part1()
     {
         var start = new State("           ",
-            $"{_crabs[0]}{_crabs[4]}",
+            $"{_crabs![0]}{_crabs[4]}",
             $"{_crabs[1]}{_crabs[5]}",
             $"{_crabs[2]}{_crabs[6]}",
             $"{_crabs[3]}{_crabs[7]}");
@@ -95,7 +99,7 @@ public sealed class Day23 : Day
     public override object Part2()
     {
         var start = new State("           ",
-            $"{_crabs[0]}DD{_crabs[4]}",
+            $"{_crabs![0]}DD{_crabs[4]}",
             $"{_crabs[1]}CB{_crabs[5]}",
             $"{_crabs[2]}BA{_crabs[6]}",
             $"{_crabs[3]}AC{_crabs[7]}");
diff --git a/AOC2021/Day24.cs b/AOC2021/Day24.cs
index 1b8bbb8..f71e873 100644
--- a/AOC2021/Day24.cs
+++ b/AOC2021/Day24.cs
@@ -8,6 +8,10 @@ public sealed class Day24 : Day
     private readonly Dictionary<int, (int x, int y)> _keys = new();
 
     public Day24() : base(2021, 24, "Arithmetic Logic Unit")
+    {
+    }
+
+    public override void ProcessInput()
     {
         var lines = Input.ToList();
         var pairs = Enumerable.Range(0, 14)
diff --git a/AOC2021/Day25.cs b/AOC2021/Day25.cs
index 1e570ed..8054bd5 100644
--- a/AOC2021/Day25.cs
+++ b/AOC2021/Day25.cs
@@ -5,9 +5,13 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day25 : Day
 {
-    private readonly char[][] _cucumbers;
+    private char[][]? _cucumbers;
 
     public Day25() : base(2021, 25, "Sea Cucumber")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _cucumbers = Input.Select(l => l.ToCharArray()).ToArray();
     }
diff --git a/AOC2022/Day01.cs b/AOC2022/Day01.cs
index aad33d7..80b6a88 100644
--- a/AOC2022/Day01.cs
+++ b/AOC2022/Day01.cs
@@ -7,9 +7,13 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day01 : Day
 {
-    private readonly List<List<int>> _elfCalories;
+    private List<List<int>>? _elfCalories;
 
     public Day01() : base(2022, 1, "Calorie Counting")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _elfCalories = Input
             .Split("")
@@ -18,7 +22,7 @@ public sealed class Day01 : Day
             .ToList();
     }
 
-    public override object Part1() => _elfCalories.First().Sum();
+    public override object Part1() => _elfCalories!.First().Sum();
 
-    public override object Part2() => _elfCalories.Take(3).Sum(e => e.Sum());
+    public override object Part2() => _elfCalories!.Take(3).Sum(e => e.Sum());
 }
diff --git a/AOC2022/Day02.cs b/AOC2022/Day02.cs
index 0467335..96c1787 100644
--- a/AOC2022/Day02.cs
+++ b/AOC2022/Day02.cs
@@ -5,9 +5,13 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day02 : Day
 {
-    private readonly List<string[]> _rounds;
+    private List<string[]>? _rounds;
 
     public Day02() : base(2022, 2, "Rock Paper Scissors")
+    {
+    }
+
+    public override void ProcessInput()
     {
         _rounds = Input.Select(line => line.Split(' ')).ToList();
     }
@@ -15,7 +19,7 @@ public sealed class Day02 : Day
     public override object Part1()
     {
         var score = 0;
-        foreach (var round in _rounds)
+        foreach (var round in _rounds!)
         {
             var me = round[1][0];
             var elf = round[0][0];
@@ -34,7 +38,7 @@ public sealed class Day02 : Day
     public override object Part2()
     {
         var score = 0;
-        foreach (var round in _rounds)
+        foreach (var round in _rounds!)
         {
             var c = round[0][0];
             switch (round[1][0])
diff --git a/AOC2022/Day03.cs b/AOC2022/Day03.cs
index 6a0f82a..45c1348 100644
--- a/AOC2022/Day03.cs
+++ b/AOC2022/Day03.cs
@@ -8,6 +8,10 @@ public sealed class Day03 : Day
     public Day03() : base(2022, 3, "Rucksack Reorganization")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
     public override object Part1() =>
         Input.Sum(rucksack => RankItem(rucksack.Chunk(rucksack.Length / 2).Aggregate<IEnumerable<char>>((a, b) => a.Intersect(b)).Single()));
diff --git a/AOC2022/Day04.cs b/AOC2022/Day04.cs
index 56cf0c8..d287295 100644
--- a/AOC2022/Day04.cs
+++ b/AOC2022/Day04.cs
@@ -5,9 +5,13 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day04 : Day
 {
-    private readonly List<(Range r1, Range r2)> _ranges;
+    private List<(Range r1, Range r2)>? _ranges;
 
     public Day04() : base(2022, 4, "Camp Cleanup")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _ranges = Input
             .Select(line => line.Split(',').SelectMany(q => q.Split('-')).Select(int.Parse).ToList())
@@ -16,8 +20,8 @@ public sealed class Day04 : Day
     }
 
     public override object Part1() =>
-        _ranges.Count(r => r.r1.Contains(r.r2) || r.r2.Contains(r.r1));
+        _ranges!.Count(r => r.r1.Contains(r.r2) || r.r2.Contains(r.r1));
 
     public override object Part2() =>
-        _ranges.Count(r => r.r1.Overlaps(r.r2));
+        _ranges!.Count(r => r.r1.Overlaps(r.r2));
 }
\ No newline at end of file
diff --git a/AOC2022/Day05.cs b/AOC2022/Day05.cs
index c7538d6..f925aec 100644
--- a/AOC2022/Day05.cs
+++ b/AOC2022/Day05.cs
@@ -7,11 +7,15 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day05 : Day
 {
-    private readonly IEnumerable<(int quantity, int from, int to)> _instructions;
-    private readonly List<Stack<char>> _stacks;
-    private readonly List<Stack<char>> _stacksPart2;
+    private IEnumerable<(int quantity, int from, int to)>? _instructions;
+    private List<Stack<char>>? _stacks;
+    private List<Stack<char>>? _stacksPart2;
 
     public Day05() : base(2022, 5, "Supply Stacks")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         var s = Input.Split("").ToList();
         var stackDiagram = s[0];
@@ -45,22 +49,22 @@ public sealed class Day05 : Day
 
     public override object Part1()
     {
-        foreach (var (quantity, from, to) in _instructions)
-            Enumerable.Range(0, quantity).ForEach(_ => _stacks[to].Push(_stacks[from].Pop()));
+        foreach (var (quantity, from, to) in _instructions!)
+            Enumerable.Range(0, quantity).ForEach(_ => _stacks![to].Push(_stacks[from].Pop()));
 
-        return PeekStackTops(_stacks);
+        return PeekStackTops(_stacks!);
     }
 
     public override object Part2()
     {
-        foreach (var (quantity, from, to) in _instructions)
+        foreach (var (quantity, from, to) in _instructions!)
         {
             var crane = new Stack<char>(quantity);
-            Enumerable.Range(0, quantity).ForEach(_ => crane.Push(_stacksPart2[from].Pop()));
+            Enumerable.Range(0, quantity).ForEach(_ => crane.Push(_stacksPart2![from].Pop()));
 
-            while (crane.Any()) _stacksPart2[to].Push(crane.Pop());
+            while (crane.Any()) _stacksPart2![to].Push(crane.Pop());
         }
 
-        return PeekStackTops(_stacksPart2);
+        return PeekStackTops(_stacksPart2!);
     }
 }
\ No newline at end of file
diff --git a/AOC2022/Day06.cs b/AOC2022/Day06.cs
index aa1aec8..7c9db8d 100644
--- a/AOC2022/Day06.cs
+++ b/AOC2022/Day06.cs
@@ -5,11 +5,19 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day06 : Day
 {
-    private readonly string _signal;
-    public Day06() : base(2022, 6, "Tuning Trouble") => _signal = Input.First();
+    private string? _signal;
+
+    public Day06() : base(2022, 6, "Tuning Trouble")
+    {
+    }
+    
+    public override void ProcessInput()
+    {
+        _signal = Input.First();
+    }
 
     private int DistinctSubstringIndex(int n) =>
-        Enumerable.Range(0, _signal.Length).First(i => _signal.Substring(i, n).Distinct().Count() == n) + n;
+        Enumerable.Range(0, _signal!.Length).First(i => _signal.Substring(i, n).Distinct().Count() == n) + n;
 
     public override object Part1() => DistinctSubstringIndex(4);
     public override object Part2() => DistinctSubstringIndex(14);
diff --git a/AOC2022/Day07.cs b/AOC2022/Day07.cs
index eb28d45..416c46b 100644
--- a/AOC2022/Day07.cs
+++ b/AOC2022/Day07.cs
@@ -8,6 +8,10 @@ public sealed class Day07 : Day
     private readonly DefaultDictionary<string, long> _dirs = new();
 
     public Day07() : base(2022, 7, "No Space Left On Device")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         var path = new Stack<string>();
         foreach (var line in Input)
diff --git a/AOC2022/Day08.cs b/AOC2022/Day08.cs
index 0aae121..96a07d2 100644
--- a/AOC2022/Day08.cs
+++ b/AOC2022/Day08.cs
@@ -5,16 +5,20 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day08 : Day
 {
-    private readonly int[][] _trees;
+    private int[][]? _trees;
 
     public Day08() : base(2022, 8, "Treetop Tree House")
+    {
+    }
+    
+    public override void ProcessInput()
     {
         _trees = Input.Select(line => line.Select(c => c - '0').ToArray()).ToArray();
     }
 
     private (bool isVisible, int scenicScore) ScoreCoord(int x, int y)
     {
-        var height = _trees[y][x];
+        var height = _trees![y][x];
         bool top = true, left = true, bottom = true, right = true;
         int upMoves = 0, leftMoves = 0, downMoves = 0, rightMoves = 0;
 
@@ -62,13 +66,13 @@ public sealed class Day08 : Day
     }
 
     public override object Part1() =>
-        Enumerable.Range(0, _trees.Length)
+        Enumerable.Range(0, _trees!.Length)
             .Sum(y => Enumerable.Range(0, _trees[0].Length).Count(x => ScoreCoord(x, y).isVisible));
 
     public override object Part2()
     {
         var max = 0;
-        for (var y = 0; y < _trees.Length; y++)
+        for (var y = 0; y < _trees!.Length; y++)
         for (var x = 0; x < _trees[0].Length; x++)
         {
             var (_, score) = ScoreCoord(x, y);
diff --git a/DayXX.cs.txt b/DayXX.cs.txt
index cf4ccca..41bb861 100644
--- a/DayXX.cs.txt
+++ b/DayXX.cs.txt
@@ -8,8 +8,18 @@ public sealed class DayXX : Day
     public DayXX() : base(YYYY, Q, "Puzzle Name")
     {
     }
+    
+    public override void ProcessInput()
+    {
+    }
 
-    public override object Part1() => "";
+    public override object Part1()
+    {
+        return "";
+    }
 
-    public override object Part2() => "";
+    public override object Part2()
+    {
+        return "";
+    }
 }