#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 7;
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(NULL);
  long long int r, g, b;
  cin >> r >> g >> b;
  long long int a[3];
  a[0] = r;
  a[1] = g;
  a[2] = b;
  sort(a, a + 3);
  cout << min((r + g + b) / 3, a[0] + a[1]);
}
