#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

using namespace std;

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

int n,x,op;
set<int>s;

int main()
{
    fin>>n;
    for(;n!=0;n--)
    {
        fin>>op>>x;
        if(op==1)
            s.insert(x);
        else if(op==2)
            s.erase(x);
        else if(op==3)
            fout<<(s.find(x)!=s.end())<<'\n';
    }

    return 0;
}