Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A definitive volume

I can understand some of the obsession around a particular number, since the college I attended has a longtime fascination with "47", and alumni use the number as a way to secretly identify each other. Nathaniel Lachenmeyer's "13", even at a manageable 200 pages, is a very thorough encyclopedia on the number 13. It's filled with facts, history, anecdotes, and period illustrations. I enjoyed reading it. Sometimes I just opened it to different pages and learned new things. It turns out there's an actual word to describe a morbid fear of the number 13: "Triskaidekaphobia". And I always wondered why none of the hotels in New York have a 13th floor (well, except for the Waldorf-Astoria, apparently). You'll have to read the book to find out for yourself why that is. "13" is a pleasant, interesting read, and a great gift.