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.
Example solution: Russian Revolution
Example explanation: This is a good example, and the Russian Revolution is the first event mentioned.

Problem: What was the year before the last battle of the Mexican-American War?, Context: The Treaty of Guadalupe Hidalgo, signed on February 2, 1848, by American diplomat Nicholas Trist and Mexican plenipotentiary representatives Luis G. Cuevas, Bernardo Couto, and Miguel Atristain, ended the war, gave the U.S. undisputed control of Texas, and established the U.S.–Mexican border of the Rio Grande. As news of peace negotiations reached the state, new call to arms began to flare among the people of the state. But as the Mexican officials in Chihuahua heard that General Price was heading back to Mexico with a large force comprising several companies of infantry and three companies of cavalry and one division of light artillery from Santa Fe on February 8, 1848, Ángel Trías sent a message to Sacramento Pass to ask for succession of the area as they understood the war had concluded. General Price, misunderstanding this as a deception by the Mexican forces, continued to advance towards the state capital. On March 16, 1848 Price began negotiations with Ángel Trías, but the Mexican leader responded with an ultimatum to General Price. The American forces engaged with the Mexican forces near Santa Cruz de los Rosales on March 16, 1848. The Battle of Santa Cruz de los Rosales was the last battle of the Mexican–American War and it occurred after the peace treaty was signed. The American forces maintained control over the state capital for three months after the confirmation of the peace treaty. The American presence served to delay the possible succession of the state which had been discussed at the end of 1847, and the state remained under United States occupation until May 22, 1848.

Solution: 1847