L = list(map(int, input().split()))

ans = 0
while True:
    L.sort()
    if L[0] > 0:
        ans += L[0]
        L[1] -= L[0]
        L[2] -= L[0]
        L[0] = 0
    else:
        if L[2] <= 1:
            break
        L[2] -= 2
        L[0] += 1
print(ans)