#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(LL i = a;i<b; i++)
#define rrep(i,a,b) for(LL i = a;i>=b; i--)
#define INF ((1LL<<62)-(1LL<<31))
#define ooki 9,223,372,036,854,775,807
#define tii -9,223,372,036,854,775,808
typedef long long LL;
int main(){
 int A,B,c,a,b;
  cin >> A >> B >> c;
  a=min(A,B);b=max(A,B);
  while(a!=b&&c>0){
    a++;
    c--;
  }
  while(c>1){
   a++;b++;c-=2;
  }
  cout<<min(a,b) <<endl;
}