module Main where

main :: IO ()
main = do
    output 1
    output [1, 2, 3]

class Show a => Output a where
    output :: a -> IO ()

instance (Show a, Num a) => Output a where
    output :: a -> IO ()
    output = print

instance (Show a, Num a) => Output [a] where
    output :: [a] -> IO ()
    output = putStr . unlines . map show