#include <bits/stdc++.h>

using namespace std;

unordered_set <int> H;

int main() {
  ifstream fin("hashuri.in");
  ofstream fout("hashuri.out");
  fin.tie(0);
  ios_base::sync_with_stdio(false);

  int n; fin >> n;

  for (int i = 0; i < n; ++ i) {
    int opType, key; fin >> opType >> key;
    if (opType == 1)
      H.insert(key);
    else if (opType == 2)
      H.erase(key);
    else
      fout << (H.find(key) != H.end()) << '\n';
  }
  fin.close();
  fout.close();
  return 0;
}