#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int r, g, b, i, x1, x2, x3, x4, x5;
  cin >> r >> g >> b;
  x4 = 0;
  x5 = 10;
  i = 0;
  while (x4 <= min(min(min(r, g), b), x5)) {
    x1 = (r - x4) / 3;
    x2 = (g - x4) / 3;
    x3 = (b - x4) / 3;
    i = max(i, x1 + x2 + x3 + x4);
    x4++;
  }
  cout << i;
  return 0;
}
