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

using namespace std;

int N, NR;
set <int> M;

int main()
{
	freopen("hashuri.in", "r", stdin);
	freopen("hashuri.out", "w", stdout);

	int i, tip, x;

	scanf("%d ", &N);

	for (i = 1; i <= N; i++) 
	{
		scanf("%d %d ", &tip, &x);

		if (tip == 1) M.insert(x);
		if (tip == 2) M.erase(x);
		if (tip == 3) printf("%d\n", M.find(x) != M.end());
	}

	return 0;
}