#include <bits/stdc++.h>
using namespace std;

int main() {
    vector<int> V;
    for (int i = 0; i < 3; i++) {
        int a;
        cin >> a;
        V.push_back(a);
    }

    int ans = 0;
    while (V[0] + V[1] + V[2] >= 3) {
        sort(V.begin(), V.end());
        if (V[0]) {
            ans += V[0];
            V[1] -= V[0];
            V[2] -= V[0];
            V[0] = 0;
        } else {
            V[2] -= 2;
            V[0]++;
        }
    }
    cout << ans << endl;
}