// 70 p. cu containerul set
#include<fstream> 
#include<set> 
using namespace std; 

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

set< int > Mult;
int N;

int main()
{
	int type, x;
	
	in >> N;
	for(int i = 1; i <= N; i++)
	{
		in >> type >> x;
		    if( type == 1 ) Mult.insert(x);
		else 
			if( type == 2 ) Mult.erase(x);
		else 
			if( type == 3 ) out << (Mult.find(x) != Mult.end()) << '\n'; 
	}
	return 0;
}