Input: Read this: In 1989, Troiden proposed a four-stage model for the development of homosexual sexual identity. The first stage, known as sensitization, usually starts in childhood, and is marked by the child's becoming aware of same-sex attractions. The second stage, identity confusion, tends to occur a few years later. In this stage, the youth is overwhelmed by feelings of inner turmoil regarding their sexual orientation, and begins to engage sexual experiences with same-sex partners. In the third stage of identity assumption, which usually takes place a few years after the adolescent has left home, adolescents begin to come out to their family and close friends, and assumes a self-definition as gay, lesbian, or bisexual. In the final stage, known as commitment, the young adult adopts their sexual identity as a lifestyle. Therefore, this model estimates that the process of coming out begins in childhood, and continues through the early to mid 20s. This model has been contested, and alternate ideas have been explored in recent years.
Question: In what year did Troiden propose a four-stage model for the development of homosexual sexual identity?

Output: 1989


Input: Read this: In a 2009 case, Netbula, LLC v. Chordiant Software Inc., defendant Chordiant filed a motion to compel Netbula to disable the robots.txt file on its web site that was causing the Wayback Machine to retroactively remove access to previous versions of pages it had archived from Nebula's site, pages that Chordiant believed would support its case.
Question: Who filed a motion to compel the Wayback Machine to disable the robots.txt file?

Output: unanswerable


Input: Read this: The Communist Party of Germany featured similar attitudes. In Die Welt, a communist newspaper published in Stockholm[e] the exiled communist leader Walter Ulbricht opposed the allies (Britain representing "the most reactionary force in the world") and argued: "The German government declared itself ready for friendly relations with the Soviet Union, whereas the English–French war bloc desires a war against the socialist Soviet Union. The Soviet people and the working people of Germany have an interest in preventing the English war plan."
Question: Who wanted war with the Nazis?

Output: unanswerable


Input: Read this: Stansted Airport, north east of London in Essex, is a local UK hub and Luton Airport to the north of London in Bedfordshire, caters mostly for cheap short-haul flights. London City Airport, the smallest and most central airport, in Newham, East London, is focused on business travellers, with a mixture of full service short-haul scheduled flights and considerable business jet traffic. London Southend Airport, east of London in Essex, is a smaller, regional airport that mainly caters for cheap short-haul flights.
Question: Which local UK airport hub is located in Essex?

Output:
Stansted Airport