#include <fstream>
#include <set>
#define mod 576101
typedef unsigned long long ll;
using namespace std;

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

set<ll> a;
int n;

int main() {
	cin >> n;
	while(n--) {
		ll h;
		int cer;
		cin >> cer >> h;
		switch(cer) {
			case 1:
				a.insert(h);
				break;
			case 2:
				a.erase(h);
				break;
			case 3:
				cout << (a.find(h) != a.end()) << '\n';
				break;
		}
	}
	return 0;
}