diff --git a/day13/main.hs b/day13/main.hs
index 871b01b..5c31e76 100755
--- a/day13/main.hs
+++ b/day13/main.hs
@@ -1,6 +1,6 @@
 #! /usr/bin/env -S"GHCRTS=-N4" nix-shell
 #! nix-shell -p ghcid
-#! nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [pretty-simple attoparsec arithmoi containers])"
+#! nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [pretty-simple attoparsec arithmoi containers parallel])"
 #! nix-shell -i "ghcid -c 'ghci' -T main"
 
 {-# OPTIONS_GHC -Wall -Wincomplete-uni-patterns #-}
@@ -27,6 +27,7 @@ import qualified Data.Attoparsec.Text as A
 import qualified Data.IntSet as I
 import qualified Data.Text as T
 import qualified Data.Vector as V
+import Control.Parallel.Strategies (parMap, parListChunk, rdeepseq)
 
 exampleData :: String
 exampleData = "939\n7,13,x,x,59,x,31,19"
@@ -98,7 +99,7 @@ isT tpx x xs = head $ catMaybes $ map go allTs
   where
     allTs = [158478605388*tpx,158478605389*tpx..]
     go :: Int -> Maybe Int
-    go tpx0 = case and (map (go' tpx0) xs) of
+    go tpx0 = case and (parMap rdeepseq (go' tpx0) xs) of
       True -> Just (tpx0 - x)
       _    -> Nothing
     go' tpx0' (shift,fact) =
@@ -145,11 +146,11 @@ main = do
   print $ 100000000000000 `mod` 631
   print $ 100000000000000 `div` 631
   putStrLn ":: Day 13 - Part 2"
-  -- print $ solvePart2 "939\n3,5"
-  -- print $ solvePart2 exampleData
-  -- print $ solvePart2 "1\n17,x,13,19"
-  -- print $ solvePart2 "1\n67,7,59,61"
-  -- print $ solvePart2 "1\n67,x,7,59,61"
-  -- print $ solvePart2 "1\n67,7,x,59,61"
-  -- print $ solvePart2 "1\n1789,37,47,1889"
+  print $ solvePart2 "939\n3,5"
+  print $ solvePart2 exampleData
+  print $ solvePart2 "1\n17,x,13,19"
+  print $ solvePart2 "1\n67,7,59,61"
+  print $ solvePart2 "1\n67,x,7,59,61"
+  print $ solvePart2 "1\n67,7,x,59,61"
+  print $ solvePart2 "1\n1789,37,47,1889"
   print $ solvePart2 input