12 pages.

Did you know that Dr. Seuss wrote Green Eggs and Ham on a bet that he couldn’t write a book with fifty or fewer distinct words?  After doing some checking, I discovered that the bet was made in 1960 with Bennett Cerf, the co-founder of Random House, and was for $50.  Ironically, even though Seuss wrote Green Eggs and Ham using EXACTLY 50 words, it's been reported that Cerf never paid up.