8000
Each of the number that is shown rounds to 0.
8000
The ISBN of The Subterraneans is 0-8021-3186-7.
The ISBN of Doctor Sax is 0-8021-3049-6.
The ISBN of Goodbye Tsugumi is 0-8021-1638-8.
The ISBN of NP - novel - is 0-8021-1545-4.
The ISBN of Lonesome Traveler is 0-8021-3074-7.
The ISBN of Malone Dies is 0-8021-5117-5.
The ISBN of Heart of a Dog is 978-0-8021-5059-2.
The ISBN of Holidays in Heck is 978-0-8021-1985-8.
The value is 0 as there are no digits underlined.
The ISBN of Mexico City Blues is 0-8021-3060-7.