#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <limits>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <complex>

using namespace std;

#define INF (INT_MAX/3)
#define PI (2*acos(0.0))
#define EPS (1e-8)

typedef long long ll;
typedef unsigned long long ull;
int rgb[3];

bool canMake(int c){
    int r = 0, s = 0;
    for(int i = 0; i < 3; i++){
        if(rgb[i] >= c) r += (rgb[i] - c) / 2;
        else s += c - rgb[i];
    }

    return r >= s;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin >> rgb[0] >> rgb[1] >> rgb[2];
    sort(rgb, rgb + 3);
    int lb = 0, ub = 10000001;
    while(lb + 1 < ub){
        int mid = (lb + ub) / 2;
        if(canMake(mid)) lb = mid;
        else ub = mid;
    }
    cout << lb << endl;
    return 0;
}