Teacher: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Teacher: Now, understand the problem? If you are still confused, see the following 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.
Solution: Russian Revolution
Reason: This is a good example, and the Russian Revolution is the first event mentioned.

Now, solve this instance: What is a formal nickname called?, Context: For example, the full name of Oda Nobunaga would be "Oda Kazusanosuke Saburo Nobunaga" (織田上総介三郎信長), in which "Oda" is a clan or family name, "Kazusanosuke" is a title of vice-governor of Kazusa province, "Saburo" is a formal nickname (yobina), and "Nobunaga" is an adult name (nanori) given at genpuku, the coming of age ceremony. A man was addressed by his family name and his title, or by his yobina if he did not have a title. However, the nanori was a private name that could be used by only a very few, including the Emperor.
Student:
yobina