import Data.Char
import Data.List
import System.Environment
import System.IO

fixInput str
  | "one" `isPrefixOf` str = '1'
  | "two" `isPrefixOf` str = '2'
  | "three" `isPrefixOf` str = '3'
  | "four" `isPrefixOf` str = '4'
  | "five" `isPrefixOf` str = '5'
  | "six" `isPrefixOf` str = '6'
  | "seven" `isPrefixOf` str = '7'
  | "eight" `isPrefixOf` str = '8'
  | "nine" `isPrefixOf` str = '9'
  | otherwise = head str

main :: IO ()
main = do
  args <- getArgs
  case args of
    [filename] -> do
      fh <- openFile filename ReadMode
      lines <- lines <$> readFile filename
      let fixed = [ [ fixInput part | part <- tails line, part /= "" ] | line <- lines ]
      let digits = map (\line -> [c | c <- line, isDigit c ]) fixed
      let numbers = map (\line -> head line : [last line]) digits
      let ints = map (\num -> read num :: Int ) numbers
      let part2 = sum ints
      print part2
    _ -> putStrLn "Missing input filename."