#include <iostream>
using namespace std;

int main() {
    int R, G, B;
    cin >> R >> G >> B;

    int maxnum = (R + G + B) / 3;
    int res;
    for (res = maxnum; res >= 0; --res) {
        int r = R - res;
        int g = G - res;
        int b = B - res;
        if (r > 0) r /= 2;
        if (g > 0) g /= 2;
        if (b > 0) b /= 2;
        if (r + g + b >= 0) break;
    }
    cout << res << endl;
}