diff --git a/AOC2020/AOC2020.csproj b/AOC2020/AOC2020.csproj
index a1bba53..44ca9e1 100644
--- a/AOC2020/AOC2020.csproj
+++ b/AOC2020/AOC2020.csproj
@@ -26,4 +26,8 @@
         <ProjectReference Include="..\AOC.Common\AOC.Common.csproj" />
     </ItemGroup>
 
+    <ItemGroup>
+      <PackageReference Include="morelinq" Version="3.3.2" />
+    </ItemGroup>
+
 </Project>
diff --git a/AOC2020/Day04.cs b/AOC2020/Day04.cs
index 669d558..224e853 100644
--- a/AOC2020/Day04.cs
+++ b/AOC2020/Day04.cs
@@ -1,3 +1,5 @@
+using MoreLinq;
+
 namespace AOC2020;
 
 /// <summary>
@@ -5,176 +7,80 @@ namespace AOC2020;
 /// </summary>
 public sealed partial class Day04 : Day
 {
-    private List<Passport>? _passports;
+    private List<Dictionary<string, string>>? _passports;
 
     public Day04() : base(2020, 4, "Passport Processing")
     {
     }
 
-    public override void ProcessInput()
+    public override void ProcessInput() =>
+        _passports = Input.Split("").Select(Parse).ToList();
+    
+    [GeneratedRegex("#[0-9a-f]{6}")]
+    private static partial Regex HexColor();
+
+    private static Dictionary<string, string> Parse(IEnumerable<string> list) =>
+        string.Join(' ', list).Split(' ', StringSplitOptions.TrimEntries)
+            .ToDictionary(k => k.Split(':', 2)[0], v => v.Split(':', 2)[1]);
+    
+    private static bool IsValid(Dictionary<string, string> d) =>
+        new[] { "byr", "iyr", "eyr", "hgt", "hcl", "ecl", "pid" }.All(d.ContainsKey);
+
+    private static bool ExtendedValidation(Dictionary<string, string> d)
     {
-        _passports = new();
+        if (!IsValid(d)) return false;
 
-        var a = new List<string>();
-        foreach (var line in Input)
+        // birth year
+        if (int.TryParse(d["byr"], out var byr))
         {
-            if (line == "")
-            {
-                _passports.Add(Passport.Parse(a));
-                a.Clear();
-                continue;
-            }
-
-            a.Add(line);
+            if (byr is < 1920 or > 2002) return false;
         }
+        else return false;
 
-        if (a.Any()) _passports.Add(Passport.Parse(a));
+        // issuance year
+        if (int.TryParse(d["iyr"], out var iyr))
+        {
+            if (iyr is < 2010 or > 2020) return false;
+        }
+        else return false;
+
+        // expiration year
+        if (int.TryParse(d["eyr"], out var eyr))
+        {
+            if (eyr is < 2020 or > 2030) return false;
+        }
+        else return false;
+
+        // height
+        if (d["hgt"].EndsWith("cm"))
+        {
+            if (int.TryParse(d["hgt"][..3], out var hgt))
+            {
+                if (hgt is < 150 or > 193) return false;
+            }
+            else return false;
+        }
+        else if (d["hgt"].EndsWith("in"))
+        {
+            if (int.TryParse(d["hgt"][..2], out var hgt))
+            {
+                if (hgt is < 59 or > 76) return false;
+            }
+            else return false;
+        }
+        else return false;
+
+        // hair color
+        if (!HexColor().IsMatch(d["hcl"])) return false;
+
+        // eye color
+        if (!new[] { "amb", "blu", "brn", "gry", "grn", "hzl", "oth" }.Contains(d["ecl"]))
+            return false;
+
+        // passport id
+        return !d.ContainsKey("pid") || d["pid"].Length == 9;
     }
 
-    public override object Part1() => _passports!.Count(p => p.IsValid);
-
-    public override object Part2() => _passports!.Count(p => p.ExtendedValidation());
-
-    private partial class Passport
-    {
-        private string? _byr;
-        private string? _cid;
-        private string? _ecl;
-        private string? _eyr;
-        private string? _hcl;
-        private string? _hgt;
-        private string? _iyr;
-        private string? _pid;
-
-        public bool IsValid =>
-            _byr != null &&
-            _iyr != null &&
-            _eyr != null &&
-            _hgt != null &&
-            _hcl != null &&
-            _ecl != null &&
-            _pid != null;
-
-        public bool ExtendedValidation()
-        {
-            if (!IsValid) return false;
-
-            // birth year
-            if (int.TryParse(_byr, out var byr))
-            {
-                if (byr is < 1920 or > 2002)
-                    return false;
-            }
-            else
-            {
-                return false;
-            }
-
-            // issuance year
-            if (int.TryParse(_iyr, out var iyr))
-            {
-                if (iyr is < 2010 or > 2020)
-                    return false;
-            }
-            else
-            {
-                return false;
-            }
-
-            // expiration year
-            if (int.TryParse(_eyr, out var eyr))
-            {
-                if (eyr is < 2020 or > 2030)
-                    return false;
-            }
-            else
-            {
-                return false;
-            }
-
-            // height
-            if (_hgt!.EndsWith("cm"))
-            {
-                var h = _hgt[..3];
-                if (int.TryParse(h, out var hgt))
-                {
-                    if (hgt is < 150 or > 193)
-                        return false;
-                }
-                else
-                {
-                    return false;
-                }
-            }
-            else if (_hgt.EndsWith("in"))
-            {
-                var h = _hgt[..2];
-                if (int.TryParse(h, out var hgt))
-                {
-                    if (hgt is < 59 or > 76)
-                        return false;
-                }
-                else
-                {
-                    return false;
-                }
-            }
-            else
-            {
-                return false;
-            }
-
-            // hair color
-            if (!HexColor().IsMatch(_hcl!))
-                return false;
-
-            // eye color
-            if (!new[] { "amb", "blu", "brn", "gry", "grn", "hzl", "oth" }.Contains(_ecl))
-                return false;
-
-            // passport id
-            return _pid == null || _pid.Length == 9;
-        }
-
-        public static Passport Parse(IEnumerable<string> list)
-        {
-            var passport = new Passport();
-            foreach (var entry in string.Join(' ', list).Split(' ', StringSplitOptions.TrimEntries))
-            {
-                var spl = entry.Split(':', 2);
-                switch (spl[0])
-                {
-                    case "byr":
-                        passport._byr = spl[1];
-                        break;
-                    case "iyr":
-                        passport._iyr = spl[1];
-                        break;
-                    case "eyr":
-                        passport._eyr = spl[1];
-                        break;
-                    case "hgt":
-                        passport._hgt = spl[1];
-                        break;
-                    case "hcl":
-                        passport._hcl = spl[1];
-                        break;
-                    case "ecl":
-                        passport._ecl = spl[1];
-                        break;
-                    case "pid":
-                        passport._pid = spl[1];
-                        break;
-                    case "cid":
-                        passport._cid = spl[1];
-                        break;
-                }
-            }
-
-            return passport;
-        }
-
-        [GeneratedRegex("#[0-9a-f]{6}")]
-        private static partial Regex HexColor();
-    }
-}
+    public override object Part1() => _passports!.Count(IsValid);
+    public override object Part2() => _passports!.Count(ExtendedValidation);
+}
\ No newline at end of file