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: "number of grand slam titles for serena williams?" whose answer is 39.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Serena Williams Grand Slam titles
Useful Output:

Doc 1: Once again Serena Williams continues her quest for a 24th Grand Slam title. Here we look back on her previous major titles.
Doc 2: Serena Williams leaves the sport with 23 Grand Slam singles titles, another 14 major championships in doubles with her older sister, Venus.
Doc 3: Serena Williams' most memorable Grand Slam victories · 1999 US Open · 2002 Wimbledon · 2003 Australian Open · 2007 Australian Open · 2012 Wimbledon.
Doc 4: Breaking up is hard to do. Now the Serena show has come to an end, relive all 23 of her grand slam titles.
Doc 5: Serena Williams's Grand Slam Titles, Finals, Records · Grand Slam Finals Appearances: 33 · Grand Slam Titles: 23 · Grand Slam Finals Record: 23-10. Top Stories