instance (Read a) => Read (IO a) where
  readsPrec d s =
    let xs = readsPrec d s in
    let m (x, s) = (return x, s) in
	map m xs

main = do
  read "123" :: IO Int
  print "Hello"
  x <- read "123" :: IO Int
  print $ "World" ++ show x
  y <- read "42"
  print $ "World" ++ showInt y

showInt :: Int -> String
showInt = show