#include <iostream>
#include <fstream>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;

typedef __gnu_pbds::gp_hash_table<int, __gnu_pbds::null_type> UnorderedSet;

int main() {
#ifdef INFOARENA
    ifstream cin("hashuri.in");
    ofstream cout("hashuri.out");
#endif
    UnorderedSet s;
    int num_queries; cin >> num_queries; 
    
    while (num_queries--) {
        int query_type, el; cin >> query_type >> el;
        if (query_type == 1) {
            s.insert(el);
        } else if (query_type == 2) {
            s.erase(el);
        } else {
            cout << (s.find(el) != s.end()) << '\n';
        }
    }

    return 0;
}