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 boston celtics win their first championship?" whose answer is 1957.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the boston celtics win their first championship
Useful Output:

Doc 1: Derrick White led the way for the Celtics in their 103-86 Game 1 win over the Magic at TD Garden.
Doc 2: The Boston Celtics won the first of their 17 championships in 1957, a 125 - 123 double-overtime thriller at the Boston Garden against the (then) St. Louis (now
Doc 3: The Boston Celtics have a chance to do something special this summer, as the team looks to become the NBA's first back-to-back champions in
Doc 4: 1957: Celtics Win First Title in 2 OT  Rookies Tommy Heinsohn and Bill Russell lead the Celtics to a 2OT victory in Game 7 of the 1957 NBA Finals. Bob Pettit
Doc 5: 1986: Celtics defeat Rockets 4-2 ▪︎ Head coach: K.C. Jones ▪︎ Larry Bird (BOS) named Finals MVP after averaging 24 points, 9.7 rebounds, 9.5