import re


def valid_passport_format(passport_number):
    """
    Checks whether a pasport number is five sets of five alpha-number characters separated by dashes
    :param passport_number: alpha-numeric string
    :return: Boolean; True if the format is valid, False otherwise
    """

    passport_regex = re.compile(r"\w\w\w\w\w-\w\w\w\w\w-\w\w\w\w\w-\w\w\w\w\w-\w\w\w\w\w")
    passport_match = passport_regex.search(passport_number)
    if passport_match is None:
        result = False
    else:
        result = True
    return result