#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<long long int> a(3);
  cin >> a[0] >> a[1] >> a[2];
  sort(a.begin(), a.end());
  cout << min(a[0] + a[1], (a[0] + a[1] + a[2]) / 3);
  return 0;
}
