#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 29;
const double EPS = 1e-9;
double zero(double d) { return d < EPS ? 0.0 : d; }
int main() {
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(8);
  ios_base::sync_with_stdio(false);
  int r, g, b;
  cin >> r >> g >> b;
  int res = 0;
  int mm = min(r, min(g, b));
  for (int i = 0; i < (int)(3); i++) {
    if (mm >= i) res = max(res, i + (r - i) / 3 + (g - i) / 3 + (b - i) / 3);
  }
  cout << res << endl;
  return 0;
}
