#include <iostream>
#include <fstream>
#include <vector>
#include <set>
using namespace std;

int main (int argc, char const *argv[])
{
	ifstream in ("hashuri.in");
	int n; in >> n;
	
	set<int> multime;
	
	ofstream out ("hashuri.out");
	for (int i = 0; i < n; i++)
	{
		int operatie; in >> operatie;
		int number; in >> number;
		switch (operatie)
		{
			case 1:
			multime.insert (number);
			break;
			
			case 2:
			multime.erase (number);
			break;
			
			case 3:
			out << (multime.find (number) != multime.end ()) << '\n';
			break;
		}
	}
	out.close ();
	
	return 0;
}