template <typename A>
class Set {
public:
    Set(){
        m_elements = std::vector<A>();
    }
    Set(const A &elem) {
        m_elements = {elem};
    }
    bool insert(const A &new_elem) {
        for (const auto &elem: m_elements) {
            if (elem == new_elem) {
                return false;
            }
        }
        m_elements.push_back(new_elem);
        return true;
    }
    bool remove(const A &to_remove) {
        for (int i = 0; i < m_elements.size(); i++) {
            if (m_elements[i] == to_remove) {
                m_elements.erase(m_elements.begin() + i);
                return true;
            }
        }
        return false;
    };
    bool operator<(Set other) {
        for (const auto &elem: m_elements) {
            if (std::find(other.m_elements.begin(), other.m_elements.end(), elem) == other.m_elements.end()) {
                return false;
            }
        }
        return true;
    };
    Set operator*(Set other) {
        Set<A> result;
        for (const auto &elem: m_elements) {
            if (std::find(other.m_elements.begin(), other.m_elements.end(), elem) != other.m_elements.end()) {
                result.insert(elem);
            }
        }
        return result;
    };
private:
    std::vector<A> m_elements;
};