In this task, you are given a context paragraph, a question based on that and corresponding answer of a question. Your task is to generate supporting fact/knowledge from context paragraph which helps in answering a given question.

Example input: North Willingham is a village and civil parish in the West Lindsey district of Lincolnshire, England. The population of the civil parish (including Sixhills) was 181 at the 2011 census. It is situated 3.5 mi east from the town of Market Rasen on the A631 road between Market Rasen and Louth. Question: Which had a bigger population at the 2011 census, North Willingham or Market Rasen? Answer: Market Rasen
Example output: Fact_1: North Willingham is a village and civil parish in the West Lindsey district of Lincolnshire, England. Fact_2: The population of the civil parish including Sixhills was 181 at the 2011 census.
Example explanation: Here, we can see that both generated facts are helpful in answering question.
Q: Sadko (Russian: , the name of the main character) is an opera in seven scenes by Nikolai Rimsky-Korsakov. The libretto was written by the composer, with assistance from Vladimir Belsky, Vladimir Stasov, and others. Rimsky-Korsakov was first inspired by the Bylina of Sadko in 1867, when he completed a tone poem on the subject, his Op. 5. After finishing his second revision of this work in 1891, he decided to turn it into a dramatic work. Question: Sadko has written and Cardillac by Hindemith is an example of operas written in which style? Answer: libretto
A:
The libretto was written by the composer, with assistance from Vladimir Belsky, Vladimir Stasov, and others.