#include <fstream>
#include <unordered_set>
using namespace std;

int main() {
  unordered_set<int> hashtable;
  ifstream in("hashuri.in");
  ofstream out("hashuri.out");
  int N, i, caseno, x;
  in>>N;
  for (i = 0; i < N; ++i) {
    in>>caseno>>x;
    switch(caseno) {
      case 1: hashtable.insert(x); break;
      case 2: hashtable.erase(x); break;
      case 3: out<<(hashtable.find(x) != hashtable.end())<<"\n"; break;
      default: return 1;
    }
  }
  in.close();
  out.close();
  return 0;
}