#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long arr[3];
  cin >> arr[0] >> arr[1] >> arr[2];
  sort(arr, arr + 3);
  cout << min(arr[0] + arr[1], (arr[0] + arr[1] + arr[2]) / 3);
  return 0;
}
