#include <iostream>
#include <fstream>
#include <unordered_map>

int main() {
    std::ifstream input("hashuri.in");
    std::ofstream output("hashuri.out");

    std::unordered_map<int, bool> hash;

    int n;
    input >> n;
    while (n--) {
        int type, x;
        input >> type >> x;
        if (type == 1) hash[x] = true;
        else if (type == 2) {
            if (hash.find(x) != hash.end()) hash.erase(x);
        }
        else {
            if (hash.find(x) != hash.end()) output << hash[x] << '\n';
            else output << "false\n";
        }
    }

    return 0;
}