#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long color[3];
  cin >> color[0] >> color[1] >> color[2];
  sort(color, color + 3);
  if ((color[0] + color[1]) * 2 <= color[2])
    cout << color[0] + color[1] << "\n";
  else
    cout << (color[0] + color[1] + color[2]) / 3 << "\n";
}
