#include <fstream>
#include <unordered_set>

using namespace std;

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

int n,c,x;
unordered_set <int> mySet;

int main()
{
	fin >> n;

	for ( int i = 0; i < n; ++i )
	{
		fin >> c >> x;

		switch (c)
		{
		    case 1 :
				mySet.insert (x);
				break;
            case 2 :
                mySet.erase (x);
                break;
            case 3 :
                fout << (mySet.find(x) != mySet.end()) << '\n';
                break;
		}
	}
}