#include<bits/stdc++.h>
#define rep(i,n,m) for(int i = (n); i <(m); i++)
#define rrep(i,n,m) for(int i = (n) - 1; i >=(m); i--)
using namespace std;
using ll = long long;

int main()
{
    int x, y, z;
    cin >> x >> y >> z;

    int ans = min(x, y);
    int res = max(x, y) - ans;
    if (res <= z)
        ans += res + (z-res)/2;
    else
        ans += z;
    cout << ans << endl;
    return 0;
}