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 was a ballet company founded who's most popular performance is a two-act ballet choreographed by Marius Petipa and Lev Ivanov?" whose answer is 1997.
Each document should contain about 30 words, and these documents should contain useful information.

Query: Mariinsky Theatre founding date
Useful Output:

Doc 1: The history of the Mariinsky Theater began on July 12, 1783, when Empress Catherine II approved the establishment of an Imperial drama,
Doc 2: The Mariinsky Theatre can trace its history as far back as 1783, when a Decree on the establishment of a theatre committee “for performances and
Doc 3: The theatre opened in 1860 and was named for Maria Aleksandrovna, wife of the reigning tsar. Ballet was not performed there until 1880 and was
Doc 4: Mariinsky Ballet. Has part(s). Mariinsky Ballet. Inception. 5 October 1783 (in Julian calendar). Date of official opening. 2 October 1860.
Doc 5: Opening of the Concert Hall of the Mariinsky Theater in 2006 was another significant date in the history of the Russian theater. This is the only theater