#include <bits/stdc++.h>
using namespace std;
bool r(const pair<long long, long long> &a,
       const pair<long long, long long> &b) {
  return (a.second < b.second);
}
long long p(long long b, long long e) { return (e == 0) ? 1 : b * p(b, e - 1); }
int main(int argc, char **argv) {
  ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
  ;
  vector<long long> a(3);
  for (long long i = 0; i < 3; i++) cin >> a[i];
  sort(a.begin(), a.end());
  cout << min(a[0] + a[1], (a[0] + a[1] + a[2]) / 3) << endl;
  return 0;
}
