def song_decoder(song):
    """
    Removes 'WUB' from a string to find the true message of the song.
    :param song: The input consists of a single non-empty string, consisting only of uppercase English letters, the string's length doesn't exceed 200 characters
    :return: the words of the initial song that Polycarpus used to make a dubsteb remix. Separate the words with a space.
    """
    return " ".join(song.replace('WUB', ' ').split())