/*

*/
#include <fstream>
#include <algorithm>
#include<vector>
#include<set>

using namespace std;

int n,m,x,y,aux,cost,caz,i,v[200010],k;

ifstream fin("hashuri.in");
ofstream fout("hashuri.out");

set<int>heap;
int main()
{

    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>caz;
        if(caz==1)
        {
            fin>>x;
            heap.insert(x);
        }
        if(caz==2)
        {
            fin>>x;
            heap.erase(x);
        }
        if(caz==3)
        {
            fin>>x;
            if(heap.find(x) != heap.end())
            {
                fout<<"1\n";
            }
            else
            {
                fout<<"0\n";
            }
        }
    }


   for(i=1;i<=k;i++)
   {
     //  fout<<v[i]<<" ";
   }

    /*for(it=heap.begin();it!=heap.end();it++)
        {
            fout<<*it<<" ";
        }*/
}