#include <iostream>
#include <string>
#include <vector>
#include <set>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <queue>
using ll = long long;
using namespace std;
int arr[3];

int add_num()
{
    //cout << arr[0] << " " << arr[1] << " " << arr[2] << endl;
    if (arr[0] == 0 && arr[1] == 0)
    {
        arr[0] += (arr[2] / 4);
        arr[1] += (arr[2] / 4);
        arr[2] -= (arr[0] + arr[1]) * 2;
    }
    else
    {
        arr[0] += (arr[2] + 1) / 2;
        arr[2] -= arr[0];
        arr[0] /= 2;
    }
    //cout << arr[0] << " " << arr[1] << " " << arr[2] << endl;
    int t = min(arr[0], min(arr[1], arr[2]));
    arr[0] -= t;
    arr[1] -= t;
    arr[2] -= t;
    return t;
}

int main(void)
{

    cin >> arr[0] >> arr[1] >> arr[2];
    //cout << arr[0] << " " << arr[1] << endl;
    sort(arr, arr + 3);

    int ans = arr[0];
    arr[2] -= arr[0];
    arr[1] -= arr[0];
    arr[0] = 0;
    while (1)
    {
        int t = add_num();
        if (t > 0)
        {
            ans += t;
            //cout << ans << endl;
        }
        else
            break;

        sort(arr, arr + 3);
    }
    cout << ans << endl;
    return 0;
}