#include<fstream>
#include<iostream>
#include<tr1/unordered_map>

using namespace std;
using namespace tr1;

unordered_map <int,int> h;

int main() {
	ifstream f("hashuri.in");
	ofstream g("hashuri.out");

	int n;
	f >> n;

	int t, x;
	for (int i = 1; i <= n; i++) {
		f >> t >> x;
		if (t == 1) {
			h[x]++;
		} else if (t == 2) {
			h.erase(x);
		} else {
			g << (h.find(x) != h.end()) << '\n';
		}
	}

	return 0;
}