http://www.colorless-sight.jp/wiki/?ProjectEular%2FProblem9
[[ProjectEular]] -- Problem 9 module Main (main) where main :: IO () main = print $ problem9 problem9 :: (Integral a) => a problem9 = head [ a*b*(1000-a-b) | a <- [1..998], b <- [(a+1)..999], a^2+b^2 == (1000-a-b)^2 ]