Input: Article: The immediate cause of the riots is unclear, with many commentators citing the killing of ten Burmese Muslims by ethnic Rakhine after the rape and murder of a Rakhine woman as the main cause. Whole villages have been "decimated". Over 300 houses and a number of public buildings have been razed. According to Tun Khin, the president of the Burmese Rohingya Organisation UK (BROUK), as of 28 June 2012, 650 Rohingyas have been killed, 1,200 are missing, and more than 80,000 have been displaced. According to the Myanmar authorities, the violence, between ethnic Rakhine Buddhists and Rohingya Muslims, left 78 people dead, 87 injured, and thousands of homes destroyed. It displaced more than 52,000 people.

Now answer this question: Who is the president of the BROUK's UK division?

Output: Tun Khin

Input: Article: Fryderyk may have had some piano instruction from his mother, but his first professional music tutor, from 1816 to 1821, was the Czech pianist Wojciech Zywny. His elder sister Ludwika also took lessons from Zywny, and occasionally played duets with her brother. It quickly became apparent that he was a child prodigy. By the age of seven Fryderyk had begun giving public concerts, and in 1817 he composed two polonaises, in G minor and B-flat major. His next work, a polonaise in A-flat major of 1821, dedicated to Zywny, is his earliest surviving musical manuscript.

Now answer this question: Who was Frederic's first professional teacher in music?

Output: Wojciech Zywny

Input: Article: Norfolk Island has 174 native plants; 51 of them are endemic. At least 18 of the endemic species are rare or threatened. The Norfolk Island palm (Rhopalostylis baueri) and the smooth tree-fern (Cyathea brownii), the tallest tree-fern in the world, are common in the Norfolk Island National Park but rare elsewhere on the island. Before European colonization, most of Norfolk Island was covered with subtropical rain forest, the canopy of which was made of Araucaria heterophylla (Norfolk Island pine) in exposed areas, and the palm Rhopalostylis baueri and tree ferns Cyathea brownii and C. australis in moister protected areas. The understory was thick with lianas and ferns covering the forest floor. Only one small tract (5 km2) of rainforest remains, which was declared as the Norfolk Island National Park in 1986.

Now answer this question: How many of the plants that can only be found on Norfolk Island are rare or threatened?

Output:
18