#include <fstream>
#include <unordered_set>

using namespace std;

int main() {
  ifstream in;
  ofstream out;

  in.open("hashuri.in");
  out.open("hashuri.out");

  int n;
  in >> n;

  int type, num;
  unordered_set<int> s;

  for (int i = 0; i < n; ++i) {
    in >> type >> num;

    switch (type) {
      case 1: s.insert(num); break;
      case 2: s.erase(num); break;
      case 3: out << (s.find(num) != s.end()) << '\n'; break;
    }
  }

  in.close();
  out.close();

  return 0;
}