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: "how many stadiums are in russia for world cup?" whose answer is twelve.
Each document should contain about 30 words, and these documents should contain useful information.

Query: "stadiums for 2018 fifa world cup russia"
Useful Output:

Doc 1: Building the World Cup: An in-depth look at Russia's stadia · Luzhniki Stadium, Moscow · Spartak Stadium, Moscow · Nizhny Novgorod Stadium, Nizhny
Doc 2: Of the twelve venues, the Luzhniki Stadium in Moscow and the Saint Petersburg Stadium—the two largest stadiums in Russia—were used most; both hosted seven
Doc 3: With a capacity of 81,000, Luzhniki, which reopened this year on the site of the 1980 Olympic stadium, is the largest of the tournament's 12
Doc 4: Russia 2018 World Cup: the complete guide to all the stadiums · Kazan Arena · Ekaterinburg Arena · Fisht Stadium · Kaliningrad Stadium · Spartak
Doc 5: World Cup Stadiums – Russia 2018 · 1. Luzhniki Stadium, Moscow · 2. Otkritie Stadium, Moscow · 3. Nizhny Novgorod Stadium, Nizhny Novgorod · 4.