#include <bits/stdc++.h>
using namespace std;
int main() {
  int r, g, b;
  cin >> r >> g >> b;
  int r1, g1, b1, r2, g2, b2;
  r1 = r / 3;
  g1 = g / 3;
  b1 = b / 3;
  r2 = r % 3;
  g2 = g % 3;
  b2 = b % 3;
  int combi = 0;
  while (r2 != 0 && g2 != 0 && b2 != 0) {
    r2 = r2 - 1;
    g2 = g2 - 1;
    b2 = b2 - 1;
    combi++;
  }
  int res = r1 + g1 + b1 + combi;
  if ((r != 0 && g != 0 && b != 0) &&
      ((r2 == 2 && g2 == 2 && b2 == 0) || (r2 == 2 && g2 == 0 && b2 == 2) ||
       (r2 == 0 && g2 == 2 && b2 == 2)))
    res++;
  cout << res << endl;
}
