R, G, B = map(int, input().split())
ans = min(R, G, B)
R -= ans
G -= ans
B -= ans
stn = [R, G, B]
can = True
while can:
    stn.sort()
    stn[0] = (stn[2] - stn[1]) // 2
    stn[2] -= stn[0] * 2
    stn.sort()
    ans += stn[0]
    if stn[0] == 0:
        can = False
    stn = [stn[i] - stn[0] for i in range(3)]
stn.sort()
ans += 2 * (min(stn[1], stn[2]) // 3)
print(ans)