#include<fstream>
#include<unordered_map>

using namespace std;

ifstream f ("hashuri.in");
ofstream g("hashuri.out");

unordered_map <int,int> map;

int n,i,x,t;

int main ()
{
	f >> n;
	
	for (i = 1; i <= n; i++)
	{
		f >> t >> x;
		if (t == 1 && map.find(x) == map.end())
			map[x] = 1;
		if (t == 2 && map.find(x) != map.end())
			map.erase (x);
		if (t == 3)
			g << (map.find(x) != map.end()) << "\n";
		else g << 0 << "\n";
	}
	f.close();
	g.close();
	return 0;
}