#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <cmath>
#include <iomanip>
#include <map>
using namespace std;
typedef long long LL;

int main(){
    int r, g, b;
    cin >> r >> g >> b;
    int ans = 0;
    for(int i = 1; i <= 10000000; i++){
        int over = max(0, r-i)/2 + max(0, g-i)/2 + max(0, b-i)/2;
        int short_cnt = max(0, i-r) + max(0, i-g) + max(0, i-b);
        if(over >= short_cnt) ans = i;
    }
    cout << ans << endl;
    return 0;
}