#include <fstream>
#include <unordered_set>
using namespace std;

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

int N;
unordered_set<int> hs;

int main() {
	fin >> N;
	while (N--) {
		int op, x;
		fin >> op >> x;
		if (op == 1)
			hs.insert(x);
		else if (op == 2)
			hs.erase(x);
		else
			fout << hs.count(x) << "\n";
	}
	return 0;
}