import           Data.Char
import           Data.List.Split


inAll :: [String] -> [Char]
inAll [first,second,third] = do
  eachChar <- first
  if (eachChar `elem` second && eachChar `elem` third) then return eachChar else []


toPriority :: Char -> Int
toPriority char = ordNum - (substract ordNum)
  where
    ordNum = (ord char)
    substract n
      | n < 97 = 38
      | otherwise = 96

main = do
  input <- readFile "three-input.txt"
  print $sum $  map (toPriority . head . inAll ) $ chunksOf 3 $ lines input
  --print $map ( inAll ) $ chunksOf 3 $ lines input