def cat_ranges_for_delete(page_count, page_numbers):
    """
    Returns a list of integers. Each number in the list
    is the number of page which will 'stay' in document.
    In other words, it returns a list with deleted pages.

    Examples:


    If document has 22 pages (page_count=22) and page number 21 is to be
    deleted (i.e page_numbers = [21]) will return

        [1, 2, 3, 4, ..., 19, 20, 22]

    If page number 1 is to be deleted:

        [2, 3, 4, ..., 22] list will be returned.

    If page number is 22 is to be deleted:

        [1, 2, 3,..., 21] will be returned.

    With  page_numbers=[1, 7, 10] and page_count=22 result
    will be:

        (2, 3, 4, 5, 6, 8, 9, 11, 12 , 13, ..., 22)


    page_numbers is a list of page numbers (starting with 1).
    """
    results = []
    for check in page_numbers:
        if not isinstance(check, int):
            err_msg = 'page_numbers must be a list of strings'
            raise ValueError(err_msg)
    for number in range(1, page_count + 1):
        if number not in page_numbers:
            results.append(number)
    return results
