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 happy meal come out?" whose answer is October 1977.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when was the first happy meal introduced
Useful Output:

Doc 1: On June 11, 1979, McDonald's introduced its first national Happy Meal promotion. Called Circus Wagon, it included six different cardboard
Doc 2: By submitting your information you agree to the Terms & Conditions and Privacy Policy and are aged 16 or over. 1987. First Disney Happy Meal is
Doc 3: Happy Meals debuted in 1979 · The first Happy Meal box was circus-themed · The iconic golden arches were always part of the Happy Meal · The first
Doc 4: First introduced as a Circus Wagon Happy Meal in June 1979 nationally in the U.S., the early iterations of the Happy Meal featured a
Doc 5: McDonald's introduced the Happy Meal — a burger, fries, drink, and a surprise toy in a themed box — to their regular menu in 1979.