#include<fstream>
#include<algorithm>
#include<unordered_set>

using namespace std;

unordered_set<int> HASH;

int main()
{
	int n,x;
	ifstream fin("hashuri.in");
	ofstream fout("hashuri.out");
	fin>>n;
	while(n--)
	{
		fin>>x;
		if(x==1)
		{
			fin>>x;
			HASH.insert(x);
			continue;
		}
		if(x==2)
		{
			fin>>x;
			HASH.erase(x);
			continue;
		}
		fin>>x;
		fout<<(HASH.find(x)!=HASH.end())<<'\n';
	}
	fin.close();
	fout.close();
	return 0;
}