#include <bits/stdc++.h>

using namespace std;

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

unordered_set <int> a;
int n;

int main()
{

    fin >> n;

    for(;n;n--)
    {
        int x,y;
        fin >> x >> y;
        if(x==1)
            a.insert(y);
        if(x==2)
            a.erase(y);
        if(x==3)
            fout << (a.find(y)!=a.end()) << "\n";
    }

    return 0;

}