#include <fstream>
#include <unordered_set>

using namespace std;

ifstream cin("hashuri.in");
ofstream cout("hashuri.out");

int main()
{
	int n;
	cin >> n;

	unordered_set<int> v;

	for (int i = 0; i < n; ++i) {
		int op, x;
		cin >> op >> x;

		if (op == 1) {
			v.insert(x);
		}
		else if (op == 2) {
			v.erase(x);
		}
		else {
			if (v.find(x) != v.end()) {
				cout << "1\n";
			}
			else {
				cout << "0\n";
			}
		}
	}

	return 0;
}