#include<iostream>
#include<fstream>
#include<set>
using namespace std;

int main()
{
	set<int> v;
	ifstream f("hashuri.in");
	ofstream g("hashuri.out");
	int n, op, x;
	f >> n;
	for (int i = 1; i <= n; i++)
	{
		f >> op >> x;
		switch (op)
		{
		case 1:
			v.insert(x);
			break;
		case 2:
			v.erase(x);
			break;
		case 3:
			if (v.find(x) != v.end())
				g << 1 << endl;
			else g << 0 << endl;
			break;
		}
	}
	f.close();
	g.close();

	int i;
	cin >> i;
	return 0;
}