#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c, maxi, mini, midi, tables;
  cin >> a >> b >> c;
  mini = min(a, min(b, c));
  maxi = max(a, max(b, c));
  midi = (a + b + c) - (mini + maxi);
  if (maxi >= 2 * (midi + mini)) {
    cout << midi + mini;
    return 0;
  }
  cout << (a + b + c) / 3;
  return 0;
}
