-- 解説を参照

import Data.List

rInt :: String -> Int
rInt = read

binarySearch :: [Int] -> Int -> Int -> Int
binarySearch rgb low high
    | high - low == 1   = low
    | check             = binarySearch rgb mid high
    | otherwise         = binarySearch rgb low mid
    where
        mid = (low + high) `div` 2
        check = (foldr chengeNum 0 (map (\x -> x - mid) rgb)) >= 0
        chengeNum x y
            | x > 0     = x `div` 2 + y
            | otherwise = x + y
    
main = do
    stones <- map rInt . words <$> getLine
    print $ binarySearch stones 0 (2^24)