def sanitize(guid: str) -> str:
    """
    Removes dashes and replaces ambiguous characters

    :param guid: guid with either dashes or lowercase letters or ambiguous letters
    :return: sanitized guid
    """
    if not guid:
        return ''
    guid = guid.replace('-', '').upper().replace('I', '1').replace('L', '1').replace('O', '0')
    return guid