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: "who has the most powerful economy in the world?" whose answer is The United States.
Each document should contain about 30 words, and these documents should contain useful information.

Query: most powerful economy in the world GDP PPP
Useful Output:

Doc 1: GDP purchasing power parity (PPP) is a way to compare the economic output and income of different countries. It's calculated by converting a
Doc 2: While the United States is the largest economy in the world in terms of nominal GDP, it is China which takes the number spot when ranked in terms of PPP.
Doc 3: The United States' GDP is the world's largest, being worth over a quarter of global output in nominal GDP terms. Moreover, it has among the
Doc 4: Dataset ; 1, China, $37.1T ; 2, U.S., $29.2T ; 3, India, $16.0T ; 4, Russia, $6.9T
Doc 5: The GDP data presented below are based on official country data published by the World Bank and IMF, in Purchasing Power Parity terms.