#include <bits/stdc++.h>

const int inf=2e9;
const int nmax=1e5;

using namespace std;

int main()
{
  ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
  freopen("hashuri.in","r",stdin);
  freopen("hashuri.out","w",stdout);

  int t;
  cin>>t;
  set<int>s;
  while(t--)
  {
    int k,x;
    cin>>k>>x;
    if(k==1) s.insert(x); else
    if(k==2) s.erase(x); else
    cout<<(s.find(x)!=s.end())<<"\n";
  }

}