Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
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Question: Passage: The concept of prime number is so important that it has been generalized in different ways in various branches of mathematics. Generally, 'prime' indicates minimality or indecomposability, in an appropriate sense. For example, the prime field is the smallest subfield of a field F containing both 0 and 1. It is either Q or the finite field with p elements, whence the name. Often a second, additional meaning is intended by using the word prime, namely that any object can be, essentially uniquely, decomposed into its prime components. For example, in knot theory, a prime knot is a knot that is indecomposable in the sense that it cannot be written as the knot sum of two nontrivial knots. Any knot can be uniquely expressed as a connected sum of prime knots. Prime models and prime 3-manifolds are other examples of this type. Question: What does it mean for a knot to be considered indecomposable?

Answer: it cannot be written as the knot sum of two nontrivial knots


Question: Passage: Emperor Gegeen Khan, Ayurbarwada's son and successor, ruled for only two years, from 1321 to 1323. He continued his father's policies to reform the government based on the Confucian principles, with the help of his newly appointed grand chancellor Baiju. During his reign, the Da Yuan Tong Zhi (Chinese: 大元通制, 'the comprehensive institutions of the Great Yuan'), a huge collection of codes and regulations of the Yuan dynasty begun by his father, was formally promulgated. Gegeen was assassinated in a coup involving five princes from a rival faction, perhaps steppe elite opposed to Confucian reforms. They placed Yesün Temür (or Taidingdi) on the throne, and, after an unsuccessful attempt to calm the princes, he also succumbed to regicide. Question: Who did Gegeen appoint as grand chancellor?

Answer: Baiju


Question: Passage: Lindisfarne are a folk-rock group with a strong Tyneside connection. Their most famous song, 'Fog on the Tyne' (1971), was covered by Geordie ex-footballer Paul Gascoigne in 1990. Venom, reckoned by many to be the originators of black metal and extremely influential to the extreme metal scene as a whole, formed in Newcastle in 1979. Folk metal band Skyclad, often regarded as the first folk metal band, also formed in Newcastle after the break-up of Martin Walkyier thrash metal band, Sabbat. Andy Taylor, former lead guitarist of Duran Duran was born here in 1961. Brian Johnson was a member of local rock band Geordie before becoming the lead vocalist of AC/DC. Question: What band is often regarded as the first folk metal group?

Answer:
Skyclad