Question: How many books are in stephen king's dark tower?

context: The Dark Tower is a series of eight books and one short story written by American author Stephen King that incorporate themes from multiple genres, including dark fantasy, science fantasy, horror, and Western. It describes a "gunslinger" and his quest toward a tower, the nature of which is both physical and metaphorical. The series, and its use of the Dark Tower, expands upon Stephen King's multiverse and in doing so, links together many of his other novels.
question: How many main story books are in stephen king's dark tower?
short_answers: eight
context: No context provided
question: How many short story books are in stephen king's dark tower?
short_answers: one

Answer: There are nine books in Stephen King's series The Dark Tower, including eight main story books and one short story book. 1982's novel The Gunslinger was the first volume in the series. The Dark Tower: The Wind Through the Keyhole is the eighth novel in the series.