#include <iostream>
#include <cmath>
using namespace std;
int r,g,b;

bool C(int x){
    int remain=0;
    int lack=0;
    if(r-x > 0){
        remain += (r-x)/2;
    }else{
        lack += abs(r-x);
    }
    if(g-x >= 0){
        remain += (g-x)/2;
    }else{
        lack += abs(g-x);
    }
    if(b-x >= 0){
        remain += (b-x)/2;
    }else{
        lack += abs(b-x);
    }
    return remain >= lack;
}
int main(void){
    cin >> r >> g >> b;
    int left = 0;
    int right = 100000009;
    while(right - left > 1 ){
        int mid = (left + right) / 2;
        if(C(mid)){
            left = mid;
        }else{
            right = mid;
        }
    }
    cout << left << endl;
    return 0;
}