def replace_umlauts(s: str) -> str:
    """
    Replace special symbols with the letters with umlauts (ä, ö and ü)

    :param s: string with the special symbols (::)
    :return: edited string
    """

    out = s.replace('A::', 'Ä').replace('O::', 'Ö').replace('U::', 'Ü').replace('a::', 'ä').replace('o::', 'ö') \
        .replace('u::', 'ü')
    return out