#include <bits/stdc++.h>   using namespace std;   int l, r, a;   int main() {     cin >> l >> r >> a;     if (l > r) swap(l, r);     if (l == r) return cout << (l + a / 2) * 2, 0;     if (l < r) {       if (l + a >= r) {         a -= abs(l - r), l = r;         cout << l * 2 + (a / 2) * 2;       } else         cout << (l + a) * 2;     }   }   