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.

Example Input: a breed is a domesticated race or type of an animal or plant.
Example Output: breed

Example Input: lee soo-young (born lee ji-yeon april 12, 1979) is a korean ballad singer.
Example Output: lee soo-young

Example Input: lord of the rings: conquest is a video game based off the award-winning science-fiction movie "the lord of the rings".
Example Output:
lord of the rings: conquest