template <class T>
set<T> set<T>:: operator* (  set <T> &s2)
{
    set <T> s(max_size + s2.max_size);
    s.size = 0;
    for (int i = 0; i < size; i++)
        cout << a[i] <<  " ";
    cout << endl;
    for (int j = 0; j < s2.size; j++)
        cout <<  s2.a[j] << " ";
    cout << endl;
    for (int i = 0; i < size; i++)
    {
        for (int j = 0; j < s2.size; j++)
            if (s2.a[j] == a[i])
            {
                s.a[s.size++] = s2.a[j];
            }
    }

    return s;
}