#include<iostream>
#include<vector>
#include<unordered_set>
#include <fstream>
using namespace std;

unordered_set <int> v;

int main() {

    ifstream input("hashuri.in");
    ofstream output("hashuri.out");

    int no, op;
    input>>no;

    for(int i = 0; i < no; i++)
    {
        input>>op;

        int x;
        input>>x;


        if ( op == 1 )
            v.insert(x);

        if ( op == 2 )
            v.erase(x);

        if ( op == 3 )
            output<<v.find(x) != v.end();
    }

    return 0;
}