In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
Which currency was used to pay Chopin?, Context: In London Chopin took lodgings at Dover Street, where the firm of Broadwood provided him with a grand piano. At his first engagement, on 15 May at Stafford House, the audience included Queen Victoria and Prince Albert. The Prince, who was himself a talented musician, moved close to the keyboard to view Chopin's technique. Broadwood also arranged concerts for him; among those attending were Thackeray and the singer Jenny Lind. Chopin was also sought after for piano lessons, for which he charged the high fee of one guinea (£1.05 in present British currency) per hour, and for private recitals for which the fee was 20 guineas. At a concert on 7 July he shared the platform with Viardot, who sang arrangements of some of his mazurkas to Spanish texts.
Answer:
guineas