#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  ios ::sync_with_stdio(0);
  long long a[3];
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  cout << min((a[0] + a[1] + a[2]) / 3, a[0] + a[1]);
  return 0;
}
