#include <cstdio>
#include <unordered_set>

using namespace std;

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

    int n, x, type;
    // unordered_set -> multime
    // unordered_map -> functie surjectiva
    unordered_set<int> H;

    scanf("%d", &n);

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

    return 0;
}