module Main where

data Direction = Upper | Lower

doHalf :: [Direction] -> (Int, Int) -> Int
doHalf ls start = fst $ foldl fn start ls 
    where fn (l, u) Lower = (l, (u+l) `div` 2)
          fn (l, u) Upper = ((u+l) `div` 2 + 1, u)

doValidate :: String -> Int
doValidate s = row * 8 + col
    where row = flip doHalf (0, 127) $ map readDir (take 7 s)
          col = flip doHalf (0, 7) $ map readDir (drop 7 s)

readDir :: Char -> Direction
readDir c
  | c `elem` "FL" = Lower
  | otherwise = Upper

main :: IO ()
main = do
    n <- lines <$> readFile "input/05"
    let valids = map doValidate n
        ans1 = maximum valids
    print ans1
    print $ sum [minimum valids .. ans1] - sum valids