#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

// #define DEBUG

void shave(vector<int> &v, int n)
{
    vector<int> x, y;
    int n_sq = sqrt(n) + 1;
    for (int i = 3; i < n + 1; i += 2)
    {
        x.push_back(i);
    }
    for (int i = 3; i < n_sq; i += 2)
    {
        for (auto itr = x.begin(); itr != x.end(); itr++)
        {
            if (*itr == i || *itr % i != 0)
                y.push_back(*itr);
        }
        x.clear();
        x = y;
        y.clear();
    }
    if (n >= 2)
        x.insert(x.begin(), 2);

    for (auto itr = x.begin(); itr != x.end(); itr++)
    {
        v.push_back(*itr);
    }
}

int main(){

#ifdef DEBUG
    cout << "DEBUG MODE" << endl;
    ifstream in("input.txt"); //for debug
    cin.rdbuf(in.rdbuf());    //for debug
#endif

    int x, y, z, p, q, w;
    cin >> x >> y >> z;
    w = 0;
    for (int i = 0; i <= z; i++){
        p = x + i, q = y + z - i;
        w = max(w, min(p, q));
    }
    cout << w << endl;
    return 0;
}

// getline(cin,s);
// a = strtok(s, ",");  ","で分解
// for (int i = 0; i < n; i++)