Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

[EX Q]: william frederick "buffalo bill" cody (february 26, 1846 – january 10, 1917) was an american soldier, bison hunter and showman.
[EX A]: buffalo bill

[EX Q]: filisur is a former municipality of the district albula in the canton of graubünden in switzerland.
[EX A]: filisur

[EX Q]: the boeing monomail was a monoplane instead of a biplane.
[EX A]:
boeing monomail