#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long int ll;

int main(){
    int a,b,c; cin >> a >> b >> c;
    int ans=min(a,b);
    a-=ans; b-=ans;
    ans+=min(max(a,b),c);
    c-=min(max(a,b),c);
    if(c>0){
        ans+=c/2;
    }
    cout << ans << endl;
}