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: "What is the name of the city where West Ham United plays and has had only fifteen permanent F.C. managers including English football manager and former professional player?" whose answer is London.
Each document should contain about 30 words, and these documents should contain useful information.

Query: number of West Ham United managers
Useful Output:

Doc 1: Potter has coached in 141 Premier League games over the course of his managerial career, winning 41 games, drawing 50 and losing 50.
Doc 2: By all accounts, now that he's taken the reins at London Stadium as West Ham's new manager, Graham Potter has his work cut out for him.
Doc 3: West Ham United has had 19 different permanent managers in its history, all with varying success. The club's first permanent manager was Syd
Doc 4: Most recent West Ham United managers · Julen Lopetegui · David Moyes · Manuel Pellegrini · Slaven Bilic · Sam Allardyce · Avram Grant · Gianfranco Zola.
Doc 5: The 49-year-old former Chelsea and Brighton & Hove Albion manager Potter was appointed as West Ham's head coach on a two-and-a-half year contract.