#include <stdio.h>
#include <ext/hash_set>

using namespace std;
using namespace __gnu_cxx;

long n, t, i, v;
hash_set<long> m;

int main() {
	freopen("hashuri.in", "r", stdin);
	freopen("hashuri.out", "w", stdout);
	
	scanf("%ld", &n);
	for (i = 1; i <= n; ++i) {
		scanf("%ld %ld", &t, &v);
		if (t == 1) m.insert(v);
		else
		if (t == 2) m.erase(v);
		else
		if (t == 3) printf("%ld\n", m.find(v) != m.end());
	}
	return 0;
}