#include<iostream>
#include<stdio.h>
#include<vector>
#include<unordered_set>
using namespace std;

unordered_set<int> v;

int main() {

  FILE *fin, *fout;
  fin = fopen("hashuri.in", "r");
  fout = fopen("hashuri.out", "w");

  int no, op;
  fscanf(fin, "%d", &no);

  for(int i = 0; i < no; i++){
    fscanf(fin, "%d", &op);

    int x;
    fscanf(fin, "%d", &x);
    switch(op){
      case 1: { v.insert(x);
                break;
              }
      case 2: { v.erase(x);
                break;
              }
      case 3: { fprintf(fout, "%d\n", v.find(x) != v.end());
                break;
              }
      default: {}
    }
  }
}