#include <iostream>
#include <cstdlib>
#include <unordered_set>
using namespace std;

int main() {
  freopen ("hashuri.in", "r", stdin);
  freopen ("hashuri.out", "w", stdout);

  unordered_set<int> hashul;

  int n; cin >> n;
  for (int i = 0; i < n; ++i) {
    int t; cin >> t;
    int x; cin >> x;

    if (t == 1) {
      hashul.insert (x);
    } else if (t == 2) {
      hashul.erase (x);
    } else {
      cout << (hashul.find(x) != hashul.end()) << "\n";
    }
  }
 
  return 0;
}