diff --git a/2023/day09/day09.hs b/2023/day09/day09.hs
index ea8ff26..f918d90 100644
--- a/2023/day09/day09.hs
+++ b/2023/day09/day09.hs
@@ -1,9 +1,7 @@
 import Control.Arrow
 
 main :: IO ()
-main = do
-  input <- parse <$> readFile "input"
-  print $ (day09 &&& day09 . map reverse) input
+main = interact $ show . (day09 &&& day09 . map reverse) . parse
 
 parse :: String -> [[Int]]
 parse = map (map read . words) . lines