#include <iostream>
#include <string>
#include <map>
#include <utility>
#include <cstdlib>
#include <vector>
#include <cstring>
#include <cstdio>
#include <cmath>
#define ll long long

using namespace std;


bool check(ll need,vector<ll> A){
    ll fusoku = 0;
    ll amari = 0;

    for(int i=0;i<3;i++){
        if(A[i] < need){
            fusoku += need - A[i];
        }else{
            amari += (A[i] - need)/2;
        }
    }
    if(fusoku <= amari)return true;
    return false;
}

int main(void){
	ll R,G,B;
    cin >> R >> G >> B;
    vector<ll> A{R,G,B};
    ll high = 10000000,low = 0;
    ll mid;

    while(low+1 < high){
        mid = (high+low)/2;
        // cout << mid << endl;
        if(check(mid,A))low = mid;
        else high = mid;
    }
    cout << low << endl;
    return 0;
}