You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

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.
Solution: Russian Revolution
Why? This is a good example, and the Russian Revolution is the first event mentioned.

New input: Who, between Mary and Aquinas, was NOT Doctor Angelicus in 1567?, Context: Popular opinion remained firmly behind the celebration of Mary's conception. In 1439, the Council of Basel, which is not reckoned an ecumenical council, stated that belief in the immaculate conception of Mary is in accord with the Catholic faith. By the end of the 15th century the belief was widely professed and taught in many theological faculties, but such was the influence of the Dominicans, and the weight of the arguments of Thomas Aquinas (who had been canonised in 1323 and declared "Doctor Angelicus" of the Church in 1567) that the Council of Trent (1545–63)—which might have been expected to affirm the doctrine—instead declined to take a position.
Solution:
Mary