#include <set>
#include <unordered_set>
#include <fstream>
#include <iostream>

using namespace std;

int main() {
  unordered_set<int> s;
  ifstream f("hashuri.in");
  ofstream g("hashuri.out");

  int n;
  f >> n;
  for (int i = 0; i < n; i++) {
    int op, x;
    f >> op >> x;

    switch (op) {
      case 1:
        s.insert(x);
        break;
      case 2:
        s.erase(x);
        break;
      case 3:
        g << (s.find(x) != s.end() ? 1 : 0) << "\n";
        break;
      default:
        std::cout << "Not supported!" << std::endl;
        break;
    }
  }

  return 0;
}