#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return !b ? a : gcd(b, a % b); }
const int LM = 1e3 + 5;
class problem {
 public:
  void init() {
    ios::sync_with_stdio(false);
    long long R, G, B;
    cin >> R >> G >> B;
    long long ans = R / 3 + G / 3 + B / 3;
    for (int i = 0; i < min(3LL, min(R, min(G, B))); i += 1)
      ans = max(ans, i + (R - i) / 3 + (G - i) / 3 + (B - i) / 3);
    cout << ans << endl;
  }
};
int main() {
  problem obj;
  obj.init();
  return 0;
}
