#include <fstream>
#include <unordered_set>

using namespace std;

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

unordered_set<int> M;
int n, x, op;

int main()
{
	fin >> n;

	for (int i = 1; i <= n; ++i) {
		fin >> op >> x;
		switch (op) {
		case 1:
			M.insert(x);
			break;
		case 2:
			M.erase(x);
			break;
		case 3:
			fout << (M.count(x)) << '\n';
			break;
		}
	}

	return 0;
}