#include <iostream>
#include <fstream>
#include <cstdlib>
#include <set>

using namespace std; 

set<int> A;

int main(){
	ifstream fin;
	ofstream fout;
	fin.open("hashuri.in");
	fout.open("hashuri.out");
	
	int N, x, y;
	fin >> N;
	
	for(cin >> x >> y; N; N--){
		if(x == 1){
			A.insert(y);
			continue;
		}

		if(x == 2){
			A.erase(y);
			continue;
		}
		
		fout << A.find(y) != A.end() << "\n"; 
	}

	fin.close();
	return 0;
}