#include <fstream>
#include <unordered_map>
using namespace std;

int main() {
	int N;
	ifstream in("hashuri.in");
	ofstream out("hashuri.out");
	unordered_map<int, int> hash;
	in>>N;
	for (int i = 0; i < N; ++i) {
		int c, x;
		in>>c>>x;
		switch (c) {
			case 1: hash.insert(make_pair(x, x)); break;
			case 2: hash.erase(x); break;
			case 3: out << (hash.find(x) != hash.end()) << "\n"; break;
			default: return -1;
		}
	}
	in.close();
	out.close();
	return 0;
}