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

int main() {
    int x, y, z;
    cin >> x >> y >> z;
    int maxi = 0;
    for (int i = 0; i <= z; i++) {
        maxi = max(maxi, min(x + i, y + z - i));
    }
    cout << maxi << endl;
}