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: When did they return?, Context: In December 1831, he joined the Beagle expedition as a gentleman naturalist and geologist. He read Charles Lyell's Principles of Geology and from the first stop ashore, at St. Jago, found Lyell's uniformitarianism a key to the geological history of landscapes. Darwin discovered fossils resembling huge armadillos, and noted the geographical distribution of modern species in hope of finding their "centre of creation". The three Fuegian missionaries the expedition returned to Tierra del Fuego were friendly and civilised, yet to Darwin their relatives on the island seemed "miserable, degraded savages", and he no longer saw an unbridgeable gap between humans and animals. As the Beagle neared England in 1836, he noted that species might not be fixed.
Output:
1836