Given the task definition, example input & output, solve the new input case.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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.
Output: Russian Revolution
This is a good example, and the Russian Revolution is the first event mentioned.

New input case for you: Who commanded the force that was sent to defeat the Western Liao, led by an usurper who had previously been the khan of the Naiman confederation?, Context: Kuchlug, the deposed Khan of the Naiman confederation that Temüjin defeated and folded into his Mongol Empire, fled west and usurped the khanate of Qara Khitai (also known as the Western Liao, as it was originally established as remnants of the Liao dynasty). Genghis Khan decided to conquer the Qara Khitai and defeat Kuchlug, possibly to take him out of power. By this time the Mongol army was exhausted from ten years of continuous campaigning in China against the Western Xia and Jin dynasty. Therefore, Genghis sent only two tumen (20,000 soldiers) against Kuchlug, under his younger general, Jebe, known as "The Arrow".
Output:
Jebe