#include <iostream>
#include <fstream>
#include <set>
using namespace std;

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

set<int> Mult;
int op, x, M;

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