diff --git a/day4/first.hs b/day4/first.hs
index 3ccea49..58fb772 100644
--- a/day4/first.hs
+++ b/day4/first.hs
@@ -40,8 +40,7 @@ finalSum = aux 0
 mark :: Integer -> Board -> Board
 mark n = map $ map conditionalMark
   where conditionalMark x
-          | n == 0 && x == 0 = -100
-          | x == n           = -x
+          | x == n           = -1
           | otherwise        = x
 
 simulate :: Integer -> [Integer] -> [Board] -> Integer
diff --git a/day4/second.hs b/day4/second.hs
index 31d812a..06d7960 100644
--- a/day4/second.hs
+++ b/day4/second.hs
@@ -45,8 +45,7 @@ finalSum = aux 0
 mark :: Integer -> Board -> Board
 mark n = map $ map conditionalMark
   where conditionalMark x
-          | n == 0 && x == 0 = -100
-          | x == n           = -x
+          | x == n           = -1
           | otherwise        = x
 
 simulate :: Integer -> [Integer] -> [Board] -> Integer