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


std::ifstream f("hashuri.in");
std::ofstream g("hashuri.out");

std::set<int> s;

int main()
{
	int n; f >> n;
	for (int i = 1; i <= n; i++) {
		int op, x;
		f >> op >> x;

		if (op == 1) s.insert(x);
		if (op == 2 && s.find(x) != s.end()) s.erase(s.find(x));
		if (op == 3) g << (s.find(x) != s.end()) << "\n";
	}

	f.close();
	g.close();
	return 0;
}