#include <iostream>
#include <set>
#include <fstream>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
set <int> st;
int n;
int main()
{
    fin>>n;
    for(int i=1;i<=n;i++)
    {
        int key,nr;
        fin>>key>>nr;
        if(key==1)st.insert(nr);
        if(key==2)st.erase(nr);
        else if(key==3)
        {
            if(st.find(nr)!=st.end())fout<<"1\n";
            else fout<<"0\n";
        }


    }
    return 0;
}