kadomatsu :: String -> [String] -> [Int]
kadomatsu n ["?", b, c] = map read [n, b, c]
kadomatsu n [a, "?", c] = map read [a, n, c]
kadomatsu n [a, b, "?"] = map read [a, b, n]

solve n ts
    | (b < a && b < c) || (b > a && b > c)  = n
    | otherwise         = ""
    where
        [a, b, c] = kadomatsu n ts

main = do
    ts <- words <$> getLine
    putStrLn $ solve "1" ts ++ solve "4" ts