Input: Read this: The term "Kievan Rus'" ( Kievskaya Rus') was coined in the 19th century in Russian historiography to refer to the period when the centre was in Kiev. In English, the term was introduced in the early 20th century, when it was found in the 1913 English translation of Vasily Klyuchevsky's A History of Russia, to distinguish the early polity from successor states, which were also named Rus. Later, the Russian term was rendered into Belarusian and Ukrainian as Kijeuskaja Rus' and Kyivs'ka Rus', respectively.
Question: What was invented in the 19th century?

Output: unanswerable

Input: Read this: Lee and freelance artist and eventual co-plotter Jack Kirby's Fantastic Four originated in a Cold War culture that led their creators to revise the superhero conventions of previous eras to better reflect the psychological spirit of their age. Eschewing such comic-book tropes as secret identities and even costumes at first, having a monster as one of the heroes, and having its characters bicker and complain in what was later called a "superheroes in the real world" approach, the series represented a change that proved to be a great success.
Question: None of the Fantastic Four had what hidden element so common to other superheroes?

Output: secret identities

Input: Read this: Fox announced on May 11, 2015 that the fifteenth season would be the final season of American Idol; as such, the season is expected to have an additional focus on the program's alumni. Ryan Seacrest returns as host, with Harry Connick Jr., Keith Urban, and Jennifer Lopez all returning for their respective third, fourth, and fifth seasons as judges.
Question: Who is returning as host?

Output: Ryan Seacrest

Input: Read this: Since 1066, when Harold Godwinson and William the Conqueror were crowned, the coronations of English and British monarchs have been held there. There have been at least 16 royal weddings at the abbey since 1100. Two were of reigning monarchs (Henry I and Richard II), although, before 1919, there had been none for some 500 years.
Question: How many royal weddings haven't occurred at the abbey?

Output:
unanswerable