#include <hash_set.h>
#include <fstream>
using namespace std;
using namespace __gnu_cxx;

hash_set< int, hash<int> > v;

int main()
{int n, x, y;
	ifstream in("hashuri.in");
	ofstream out("hashuri.out");
	in>>n;
	for( ; n; --n )
	{
		in>>x>>y;
		switch( x )
		{
			case 1: v.insert(y); break;
			case 2: v.erase(y); break;
			case 3: out<<( v.end() != v.find(y))<<'\n'; break;
		}
	}
	return 0;
}