diff --git a/2020/day10/day10.hs b/2020/day10/day10.hs
index f78f2cd..a31aaaf 100644
--- a/2020/day10/day10.hs
+++ b/2020/day10/day10.hs
@@ -9,11 +9,9 @@ main = do
     (product . map (arrangements . sum) . filter (elem 1) . group . jolts) input
 
 arrangements :: Int -> Int
-arrangements n =
-  length $
-  filter (== n) $ map sum $ nub $ map (filter (/= 0)) $ replicateM n [0 .. 3]
+arrangements =
+  (\x -> length . filter (== x)) <*>
+  (map sum . nub . map (filter (/= 0)) . flip replicateM [0 .. 3])
 
 jolts :: [Int] -> [Int]
-jolts =
-  ap (zipWith subtract) tail .
-  ap (++) (flip (:) [] . (+ 3) . last) . (:) 0 . sort
+jolts = ap (zipWith subtract) tail . (\x -> 0 : x ++ [last x + 3]) . sort