#include <fstream>
#include <map>

int main() {
	std::ifstream cin("hashuri.in");
	std::ofstream cout("hashuri.out");
	std::ios::sync_with_stdio(false);
	int n, op_type, x;
	
	cin >> n;
	std::map<int, int> map;
	for (int i = 0 ; i < n ; ++i) {
		cin >> op_type >> x;
		switch(op_type) {
			case 1: map[x++];
					break;
			case 2: map.erase(x);
					break;
			default: cout << (map.find(x) != map.end()) << '\n';
		}
	}

	return 0;
}