import IO
import System (getArgs)
    
main = do
  args <- getArgs
  let acts = map output args
  sequence_ acts
    
output f = do
  l <- countLinesFile f
  putStrLn (f ++ ": " ++ show l)
    
countLinesFile f = do
  h <- openFile f ReadMode
  hCountLines h
    
hCountLines h = do
  x <- hGetContents h
  return (length (lines x))