#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

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

    int ans = 0;

    while(true){
        if(x > 0 && y > 0){
            ans++;
            x--;
            y--;
        }else if(x > 0){
            if(z == 0)break;
            z--;
            x--;
            ans++;
        }else if(y > 0){
            if(z == 0)break;
            z--;
            y--;
            ans++;
        }else{
            if(z < 2)break;
            z -= 2;
            ans++;
        }
    }

    cout << ans << endl;
    return 0;
}