S = sorted(map(int, input().split()))
a = S[0]
for i in range(3):
    S[i] -= a
while S[1] != 0 and S[2] > 2:
    b = min(S[1], S[2] // 3)
    a += b
    S[1] -= b
    S[2] -= b * 3
    S.sort()
a += S[2] // 5
print(a)