#include <fstream>
#include <map>



int main()
{
	int n,op,arg;
	std::ifstream fin("hashuri.in");
	std::ofstream fout("hashuri.out");
    std::map<int, bool> test;
    fin>>n;
    for (int i = 0; i < n; ++i)
	{
		fin>>op>>arg;
		switch(op)
		{

			case 1:
				test[arg] = true;
				break;
			case 2:
				test.erase(arg);
				break;
			case 3:
				fout<<(test.find(arg) != test.end())<<"\n";
				break;

		}
	}
	fout.close();
	fin.close();
	return 0;
}