#include <iostream>
#include <fstream>
#include <unordered_set>

using namespace std;

int main()
{
    ifstream cin("hashuri.in");
    ofstream cout("hashuri.out");

    int n;
    cin >> n;

    unordered_set<int> H;
    while (n--) {
        int op, x;
        cin >> op >> x;

        switch (op) {
        case 1:
            H.insert(x);
            break;
        case 2:
            H.erase(x);
            break;
        case 3:
            cout << (H.find(x) != H.end()) << '\n';
            break;
        }
    }

    return 0;
}