import Data.List (isPrefixOf)
import System.Environment (getArgs)

main = do
  args <- getArgs
  mapM_ identify args

identify f = do
  g <- catch (isInteresting f) handler
  case g of
    Just h -> putStrLn (f ++ ": " ++ if h then "interesting" else "boring")
    Nothing -> return ()
  where
    handler e = do
               print e
               return Nothing

isInteresting f = do
  x <- readFile f
  return (Just (x `contains` "Haskell"))

[] `contains` _ = False
(x:xs) `contains` y = y `isPrefixOf` (x:xs) || xs `contains` y