#include <bits/stdc++.h>

using namespace std;

int main() {
    ifstream cin("hashuri.in");
    ofstream cout("hashuri.out");
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int n; cin >> n;
    
    unordered_set<int> m_hash;
    //m_hash.reserve(1 << 20);
    //m_hash.max_load_factor(0.25);

    while (n--) {
        int op_type, x; cin >> op_type >> x;
        if (op_type == 1) {
            m_hash.insert(x);
        } else if (op_type == 2) {
            m_hash.erase(x);
        } else {
            cout << (m_hash.find(x) != m_hash.end()) << '\n';
        }
    }

    return 0;
}