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

int main(){
    int a, b, c;
    cin >> a >> b >> c;
    int ans = min(a, b);
    int d = abs(a-b);
    ans += min(c, d);
    if (c > d) ans += (c-d)/2;
    cout << ans << endl;
    return 0;
}