#include <fstream>
#include <set>
using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");
set <int> Treap;

int main()
{
	int n,tip,x;
	fin>>n;
	
	for(;n;--n)
	{
		fin>>tip >>x;
		if(tip==1)
			Treap.insert(x);
		else
		if(tip==2)
			Treap.erase(x);
		else
		if(tip==3)
			fout<< (Treap.find(x)!=Treap.end())<<'\n';
	}
	
	return 0;
}