In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Input: Consider Input: Passage: Indigenous peoples inhabited Missouri for thousands of years before European exploration and settlement. Archaeological excavations along the rivers have shown continuous habitation for more than 7,000 years. Beginning before 1000 CE, there arose the complex Mississippian culture, whose people created regional political centers at present-day St. Louis and across the Mississippi River at Cahokia, near present-day Collinsville, Illinois. Their large cities included thousands of individual residences, but they are known for their surviving massive earthwork mounds, built for religious, political and social reasons, in platform, ridgetop and conical shapes. Cahokia was the center of a regional trading network that reached from the Great Lakes to the Gulf of Mexico. The civilization declined by 1400 CE, and most descendants left the area long before the arrival of Europeans. St. Louis was at one time known as Mound City by the European Americans, because of the numerous surviving prehistoric mounds, since lost to urban development. The Mississippian culture left mounds throughout the middle Mississippi and Ohio river valleys, extending into the southeast as well as the upper river.
Link Information: earthworks are artificial changes in land level, typically made from piles of artificially placed or sculpted rocks and soil. Question: What are earthwork mounds made of?

Output: Answer: sculpted rocks and soil.

Input: Consider Input: Passage: It was in the 1991-92 season of TV's Murphy Brown starring Candice Bergen, Elder made a mark portraying Murphy Brown's obstetrician, Dr. Barton. Her recurring role culminated with the historic season finale where Dr. Barton delivered Murphy Brown's baby. She was cast as Gina's mother Nadine Water's on Martin (199297) starring Martin Lawrence. And in 1998 she replaced Jo Marie Payton as Harriette Winslow in the last several episodes of the popular show Family Matters. Elder has frequently returned to the stage and having last appeared at Arkansas Rep as Rose in August Wilson's Fences. She also has many theatre directorial credits including: The Book of the Crazy African (Skylight Theatre), The Meeting (Inner City Cultural Center, LA and New Federal Theatre, NY), Ceremonies in Dark Old Men (Beverly Canon Theatre), and A Private Act (Robey Theatre Company). Her direction of Matthew Lopez' The Whipping Man starring Charlie Robinson at the Skirball Cultural Center for LA Theatre Works radio series was broadcast nationally in 2016. Elder is an alumna of the American Film Institute's Directing Workshop for Women where she produced and directed the short film, Behind God's Back, based on an Alice Walker short story and starring Beau Bridges. She is also the recipient of a Screenwriting Fellowship with Walt Disney Studios. In 2005, Elder was honored with an NAACP Trailblazer Award. Elder is also a 2010 recipient of a Distinguished Alumni Award from Emerson College.
Link Information: And in 1998 she replaced Jo Marie Payton as Harriette Winslow in the last several episodes of the popular show Family Matters. Question: Which show that Elder has worked went on for a longer period of time, the show where she played Harriette Winslow or the show where she was cast as an obstetrician?

Output: Answer: Murphy Brown

Input: Consider Input: Passage: The military history of the Aleutian Islands began almost immediately following the purchase of Alaska from the Russian Empire by the United States in 1867. Prior to the early 20th century, the Aleutian Islands were essentially ignored by the United States Armed Forces, although the islands played a small role in the Bering Sea Arbitration when a number of British and American vessels were stationed at Unalaska to enforce the arbitrators' decision. By the early 20th century, a number of war strategies examined the possibility of conflict breaking out between the Empire of Japan and the United States. While the Aleutian Islands were seen as a potential staging point for invasions by either side, this possibility was dismissed owing to the islands' dismal climate. In 1922, the Washington Naval Treaty was signed, after which the United States Navy began to take an interest in the islands. However, nothing of significance was to materialize until World War II.
Link Information: The sittings of the tribunal began in February 1893 and ended in August. Question: How long did the arbitration in which the islands played a small role last?
Output: Answer: 6