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

ifstream is("hashuri.in");
ofstream os("hashuri.out");

set<int> A;
int n;

int main()
{
	int op, x;
	is >> n;
	for(int i = 1; i<= n; ++i)
	{
		is >> op >> x;
		if(op == 1)
		{	
			A.insert(x);	
		}
		else
		if(op == 2)
		{	
			A.erase(x);		
		}
		else
		if(op == 3)
		{
			os << (A.find(x) != A.end()) << '\n';
		}
	
	}
	is.close();
	os.close();
	return 0;
}