#include <cstdio>
#include <tr1/unordered_set>


using namespace std;


int main()
{
	tr1::unordered_set<int> H;	
	int n, p, q;
	freopen ("hashuri.in", "r", stdin);
	freopen ("hashuri.out", "w", stdout);
	scanf ("%d\n", &n);

	while (n--)
	{
		scanf ("%d %d\n", &p, &q);

		if (p == 1)
			H.insert (q);
		if (p == 2)
			H.erase (q);
		if (p == 3)
			printf ("%d\n", H.find(q) == H.end() ? 0 : 1);

	}

	return 0;
}