breakLine :: Int -> String -> String
breakLine maxlen = go [] . words
  where
  go acc []     = acc
  go []  (w:ws) = go w ws
  go acc (w:ws)
    | length acc' <= maxlen = go acc' ws
    | otherwise             = acc ++ "\n" ++ go w ws
    where acc' = acc ++ " " ++ w

main = interact (unlines . map (breakLine 80) . lines)