#include <bits/stdc++.h>
using namespace std;
int main() {
  long long r, g, b;
  cin >> r >> g >> b;
  bool a = true;
  if (!r || !g || !b) a = false;
  long long ans = 0;
  ans = (r / 3) + (g / 3) + (b / 3);
  long long v[3] = {0};
  v[r % 3]++;
  v[g % 3]++;
  v[b % 3]++;
  ans += min((r % 3), min((g % 3), (b % 3)));
  if (v[2] == 2 && v[0] == 1 && a)
    cout << ans + 1;
  else
    cout << ans;
}
