#include <stdio.h>
#include <set>

using namespace std;

int N; 
set<N> A;

int main()
{
	int op, x;

	freopen("hashuri.in", "r", stdin);
	freopen("Hashuri.out", "w", stdout);

	for (scanf("%d", &N); N; --N)
	{
		scanf("%d %d", &op, &x);
		if (op == 1)
		{
			A.insert(x);
		} 
		else if (op == 2)
		{
			A.erase(x);
		}
		else 
		{
			printf("%d\n", A.find(x) != A.end());
		}
	}
	return 0;
}