instruction:
Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
question:
Passage: Computational complexity theory is a branch of the theory of computation in theoretical computer science that focuses on classifying computational problems according to their inherent difficulty, and relating those classes to each other. A computational problem is understood to be a task that is in principle amenable to being solved by a computer, which is equivalent to stating that the problem may be solved by mechanical application of mathematical steps, such as an algorithm. Question: What branch of theoretical computer science deals with broadly classifying computational problems by difficulty and class of relationship?
answer:
Computational complexity theory


question:
Passage: The two most prominent Norman families to arrive in the Mediterranean were descendants of Tancred of Hauteville and the Drengot family, of whom Rainulf Drengot received the county of Aversa, the first Norman toehold in the south, from Duke Sergius IV of Naples in 1030. The Hauteville family achieved princely rank by proclaiming prince Guaimar IV of Salerno 'Duke of Apulia and Calabria'. He promptly awarded their elected leader, William Iron Arm, with the title of count in his capital of Melfi. The Drengot family thereafter attained the principality of Capua, and emperor Henry III legally ennobled the Hauteville leader, Drogo, as 'dux et magister Italiae comesque Normannorum totius Apuliae et Calabriae' ('Duke and Master of Italy and Count of the Normans of all Apulia and Calabria') in 1047. Question: Who was Count of Melfi
answer:
William Iron Arm


question:
Passage: Southern California consists of one Combined Statistical Area, eight Metropolitan Statistical Areas, one international metropolitan area, and multiple metropolitan divisions. The region is home to two extended metropolitan areas that exceed five million in population. These are the Greater Los Angeles Area at 17,786,419, and San Diego–Tijuana at 5,105,768. Of these metropolitan areas, the Los Angeles-Long Beach-Santa Ana metropolitan area, Riverside-San Bernardino-Ontario metropolitan area, and Oxnard-Thousand Oaks-Ventura metropolitan area form Greater Los Angeles; while the El Centro metropolitan area and San Diego-Carlsbad-San Marcos metropolitan area form the Southern Border Region. North of Greater Los Angeles are the Santa Barbara, San Luis Obispo, and Bakersfield metropolitan areas. Question: What is the population of the Greater Los Angeles Area?
answer:
17,786,419