#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define P(x) cout << (x) << "\n"
#define D(x) cerr << (x) << "\n"
#define fcout cout << fixed << setprecision(18)

using i64 = long long int; // 10^18

i64 r, g, b;
bool isOK(i64 n)
{
    vector<i64> v({r - n, g - n, b - n});
    i64 c = 0;
    for(auto i:v){
        c += (i>0)?i/2:i;
    }
    return c<0;
}

i64 binary_search()
{
    i64 ng = 0;
    i64 ok = pow(2, 24);

    while (abs(ok - ng) > 1)
    {
        i64 mid = ng + (ok - ng) / 2;
        if (isOK(mid))
            ok = mid;
        else
            ng = mid;
    }
    return ok;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> r >> g >> b;
    P(binary_search());
    return 0;
}