#include <bits/stdc++.h>
using namespace std;
int main() {
  int r;
  int g;
  int b;
  cin >> r >> g >> b;
  bool verif;
  verif = (r == 0 || g == 0 || b == 0);
  int res = 0;
  res += r / 3;
  res += g / 3;
  res += b / 3;
  r %= 3;
  g %= 3;
  b %= 3;
  int m;
  m = min(r, g);
  m = min(m, b);
  res += m;
  if (((r + g + b) == 4) && ((r == 0) || (g == 0) || (b == 0)) && !(verif)) {
    res++;
  }
  cout << res;
}
