You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did the first harry potter book come put?" whose answer is 26 June 1997.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when was the first harry potter book published
Useful Output:

Doc 1: By far the most valuable book in the series is the first, Harry Potter and the Philosopher's Stone, published on 30 June 1997 by Bloomsbury in
Doc 2:  first Harry Potter book in the shops. It's 20 years since Harry Potter and the Philosopher's Stone was published. Rowling was interviewed by
Doc 3: The publication of the first edition of Harry Potter and the Philosopher's Stone on 26 June 1997 mark the very first time we were introduced to Harry.
Doc 4: Harry Potter was first introduced in the novel Harry Potter and the Philosopher's Stone (1997; also published as Harry Potter and the
Doc 5: For example, the first edition of Harry Potter and the Chamber of Secrets was published in the UK by Bloomsbury in 1998. To verify its