def f(a, b, c):
    L = [a, b, c]
    L.sort()
    v = (L[-1] - L[0])//3
    L[-1] -= 2 * v
    L[0] += v
    return L[0], L[1], L[2]

R, G, B = map(int, input().split())
for i in range(10):
    R, G, B = f(R, G, B)
print(min(R, G, B))