#include <cstdio>
#include <map>

using namespace std;

int n, i, y, x;
map <int, int> a;

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

	for(scanf("%d ", &n); n; --n)
	{
	    scanf("%d %d", &y, &x);

		if (y == 1)
		{
		    a[x]=1;
		    continue;
		}
		if (y == 2)
		{
		    a.erase(x);
		    continue;
		}
		if (y == 3)
		{
		    printf("%d\n", a.find(x)!=a.end());
		    continue;
		}
	}

	return 0;
}