diff --git a/05.hs b/05.hs
index 56de949..9dcf8ab 100644
--- a/05.hs
+++ b/05.hs
@@ -1,4 +1,5 @@
-import Data.IntMap (IntMap, insert, fromList, findWithDefault)
+{-# LANGUAGE BangPatterns #-}
+import Data.IntMap.Strict (IntMap, insert, fromList, findWithDefault)
 
 type State = (Int, Int, IntMap Int)
 type Update = Int -> Int
@@ -9,12 +10,12 @@ next f (steps, i, jumps) =
     in  (steps + 1, i + value, insert i (f value) jumps)
 
 getExitSteps :: Int -> Update -> State -> Int
-getExitSteps len f (steps, i, jumps) =
-    if i >= len then steps else getExitSteps len f $! next f (steps, i, jumps)
+getExitSteps len f (!steps, i, jumps) =
+    if i >= len then steps else getExitSteps len f $ next f (steps, i, jumps)
 
 main :: IO ()
 main = do
-    jumpsList <- fmap (map read . lines) $ readFile "5.txt"
+    jumpsList <- fmap (map read . lines) $ readFile "05.txt"
     let jumpsMap  = fromList $ zip [0..] jumpsList
     print $ getExitSteps (length jumpsList) (+1)                                    (0, 0, jumpsMap)
     print $ getExitSteps (length jumpsList) (\v -> if v >= 3 then v - 1 else v + 1) (0, 0, jumpsMap)
\ No newline at end of file