#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int c0, c1, c2;
  int max;
  c0 = a / 3 + b / 3 + c / 3;
  c1 = (a - 1) / 3 + (b - 1) / 3 + (c - 1) / 3 + 1;
  if (a < 1 || b < 1 || c < 1) c1 -= 1;
  c2 = (a - 2) / 3 + (b - 2) / 3 + (c - 2) / 3 + 2;
  if (a < 2 || b < 2 || c < 2) c2 -= 2;
  max = c0;
  if (c1 > c0) max = c1;
  if (c2 > c0) max = c2;
  cout << max << endl;
  return 0;
}
