#include <cstdio>
#include <cassert>
#include <algorithm>
#include <unordered_set>
using namespace std;
#define _submit
#ifdef _submit
#define InFile "hashuri.in"
#define OtFile "hashuri.out"
#else
#define InFile "fis.in"
#define OtFile "fis.out"
#endif

unordered_set<int> M;

int main() {
	assert(freopen(InFile, "r", stdin));
	assert(freopen(OtFile, "w", stdout));
	int N;
	scanf("%d", &N);
	M.reserve(N);
	while (N--) {
		int op, nr;
		scanf("%d%d", &op, &nr);
		switch(op) {
		case 1:
			M.insert(nr);
			break;
		case 2:
			M.erase(nr);
			break;
		case 3:
			printf("%d\n", M.find(nr) != M.end());
			break;
		default:
			break;
		}
	}
	return 0;
}