diff --git a/src/3n+1/Main.hs b/src/3n+1/Main.hs
index fa64876..2e22911 100644
--- a/src/3n+1/Main.hs
+++ b/src/3n+1/Main.hs
@@ -3,11 +3,17 @@ The Simplest Math Problem No One Can Solve - Collatz Conjecture
 https://youtu.be/094y1Z2wpJg
 -}
 
-import           Control.Monad ()
-import           Debug.Trace   (trace)
+import           Control.Parallel.Strategies
+import           Data.Set                    (fromList)
+import           Debug.Trace                 (trace)
 
 main :: IO ()
-main = print $ take 100 $ map f [2^1000..]
+main = print $ fromList $ take 300 $ parMap rpar f [2^100_000..]
+-- main = print $ fromList $ take 300 $ map f [2^100_000..]
+  -- fromList [100001,717859]
+
+-- main = print $ fromList $ take 3 $ map f [2^310997..]
+-- main = print $ f $ 2^310997 + 2
 
 f :: Integer -> Integer
 f n = s 1 n