#include <fstream>
#include <iostream>
#include <algorithm>
#include <unordered_set>

using namespace std;

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

int x, n, op;
unordered_set<int> us;

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

    }
    return 0;
}