#!/usr/bin/env runhaskell
  main = putStrLn (
   show "2" ++
   show (foldl (-) 1 [2..6]) ++ " " ++
   show (foldr (-) 6 [1..5] ) ++ " " ++
   show (foldl1 (-) [1..6] ) ++ " " ++
    show (foldr1 (-) [1..6] )
    )