#include <bits/stdc++.h> using namespace std::literals::string_literals; using i64 = long long; using std::cout; using std::endl; using std::cin; template<typename T> std::vector<T> make_v(size_t a){return std::vector<T>(a);} template<typename T,typename... Ts> auto make_v(size_t a,Ts... ts){ return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...)); } int main() { int x, y, z; scanf("%d%d%d", &x, &y, &z); int A = std::min(x, y); int B = std::max(x, y); int C = std::min(z, B - A); printf("%d\n", A + C + (z - C) / 2); return 0; }