def toc2plaintext(toc: list) -> str:
    """
    :param toc: table of content <- DOCUMENT.get_toc()
    :return: plaintext
    """
    plaintext = []
    for content in toc:
        head = f'{int(content[0])*"*"}-->{content[1]}-->{content[2]}'
        plaintext.append(head)
    plaintext = '\n'.join(plaintext)
    return plaintext