#include <set>

using namespace std;

int main() {
    set<int> s;

	freopen("hashuri.in", "r", stdin);
	freopen("hashuri.out", "w", stdout);

    int n;
	scanf("%d ", &n);

    for (int i = 0; i < n; i++) {
        int op, x;
		scanf("%d %d ", &op, &x);
        switch(op) {
            case 1:
                if (s.find(x) == s.end()) {
                    s.insert(x);
                }
                break;
            case 2:
                s.erase(x);
                break;
            case 3:
                printf("%d\n", s.find(x) != s.end());
                break;
        }
    }

    return 0;
}