#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int arr[3], ans = 0;
  cin >> arr[0] >> arr[1] >> arr[2];
  sort(arr, arr + 3);
  if (2 * (arr[0] + arr[1]) <= arr[2]) {
    cout << arr[0] + arr[1] << "\n";
  } else
    cout << (arr[0] + arr[1] + arr[2]) / 3 << "\n";
  return 0;
}
