#include <iostream>
#include <fstream>
#include <set>

int main() {
	std::set<int> hash;
	int N;

	int option, x;
	bool is_in;

	std::fstream in("hashuri.in", std::ios::in);
	std::fstream out("hashuri.out", std::ios::out);

	in >> N;

	for (auto i = 0; i < N; i++) {
		in >> option;
		in >> x;

		switch (option) {
		case(1):
			hash.insert(x);
			break;

		case(2):
			hash.erase(x);
			break;

		case(3):
			is_in = hash.find(x) != hash.end();
			out << is_in;
			break;
		default:
			break;
		}
	}
}