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

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    unordered_set<int> hashSet;

    int n, x, y;
    cin >> n;

    while (n--) {
        cin >> x >> y;

        if (x == 1) {
            hashSet.insert(y);
        } else if (x == 2) {
            hashSet.erase(y);
        } else if (x == 3) {
            cout << (hashSet.count(y) ? 1 : 0) << '\n';
        }
    }

    return 0;
}