import Data.Char (ord, isLower, isUpper)
import Data.List (intersect)
import Data.List.Split (chunksOf)

priority :: Char -> Int
priority c
    | isLower c = ord c - ord 'a' + 1
    | isUpper c = ord c - ord 'A' + 27

splitHalf :: [a] -> ([a],[a])
splitHalf xs = splitAt (length xs `div` 2) xs

findDup :: String -> Char
findDup s = head $ intersect l r where
    (l, r) = splitHalf s

groupDup :: [String] -> Char
groupDup = head . foldr1 intersect

main :: IO ()
main = do
    x <- lines <$> getContents
    let dups = map findDup x
    
    -- part 1
    putStr "part 1: "
    print $ sum (map priority dups)

    -- part 2
    let groups = chunksOf 3 x
    putStr "part 2: "
    print $ sum (map (priority . groupDup) groups)