#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  long long a, b, c, d, e, f, g, mn;
  cin >> a >> b >> c;
  d = min(a, min(b, c));
  a -= d, b -= d, c -= d;
  if (a % 3 + b % 3 + c % 3 == 4 && d != 0) d++;
  cout << d + a / 3 + b / 3 + c / 3;
}
