Hi Haskellers, I encounter an strange behavior of haskell program recently. The following is my program ```haskell main = do _ <- getLine arr1 <- getLine _ <- getLine arr2 <- getLine let a = map (read :: String -> Int) (words arr1) b = map (read :: String -> Int) (words arr2) putStrLn $ show $ (foldl (*) 1 a) putStrLn $ show $ a == [1,2,4,8,32,64,128,256,512,1024,2048,4906,8192] putStrLn $ show $ (foldl (*) 1 [1,2,4,8,32,64,128,256,512,1024,2048,4906,8192]) ``` With the input test file as following: ```test.in 13 1 2 4 8 32 64 128 256 512 1024 2048 4906 8192 9 1 3 9 27 81 243 729 2187 6561 ``` The output is as: ```output 0 True 185343439719667835347140608 ``` In fact, from the program, we know that a is equal to list [1,2,4,8,32,64,128,256,512,1024,2048,4906,8192] , but the product of a and the literal list is different. Can anyone tell me why? Thanks --m00nlight