title: Vicuña
context: The vicuña (Vicugna vicugna) or vicuna[2] (both /vɪˈkuːnjə/, very rarely spelled vicugna, which is actually the name of its genus)[3][4] is one of the two wild South American camelids which live in the high alpine areas of the Andes, the other being the guanaco. It is a relative of the llama, and is now believed to be the wild ancestor of domesticated alpacas, which are raised for their coats. Vicuñas produce small amounts of extremely fine wool, which is very expensive because the animal can only be shorn every three years, and has to be caught from the wild. When knitted together, the product of the vicuña's wool is very soft and warm. The Inca valued vicuñas highly for their wool, and it was against the law for anyone but royalty to wear vicuña garments; today the vicuña is the national animal of Peru and appears in the Peruvian coat of arms.
question: What is the most expensive type of wool?
answers: vicuña