#include <fstream>
#include <hash_set>
using namespace std;
using namespace __gnu_cxx;

ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
hash_set<int, hash<int> > H;

int main() {
  int t;
  for (fin >> t; t; --t) {
    int op, val;
    fin >> op >> val;
    switch (op) {
      case 1: H.insert(val); break;
      case 2: H.erase(val); break;
      default: fout << (H.find(val) != H.end()) << "\n";
    }
  }
  return 0;
}