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.
--------
Question: the wii u is a video game console that was released by nintendo on november 18, 2012, and is the successor of the wii.

Answer: wii u

Question: the channel catfish (scientific name:"ictalurus punctatus"), also called the channel cat, is a species of catfish.

Answer: channel catfish

Question: hou zongbin (; january 1929 14 november 2017) was a chinese politician.

Answer:
hou zongbin