class Solve:
    def __init__(self):
        self.S = [int(i) for i in input().split()]

        self.a = min(self.S) # >= 0; True
        self.b = max(self.S)+1  # <= 10**7+1; False

    def solve(self):
        S = sorted(self.S)
        m = S.pop(0)
        n = m
        S0, S1 = [s-m for s in S]

        # S0とS1を同じ数にしようとする
        d = (S1 - S0)//2
        # S0とS1を同じ数又は1個差にできる場合
        if S0 >= S1//3:
            n += (S0 + S1)//4 - int(S0 - d == S1 - 3*d == 2)
        # 先にS0枯渇 && 残りのS1が5個で1個生成
        else:
            n += S0 + (S1 - 3*S0)//5

        return n

print(Solve().solve())