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 Input:
cumulative voting is a system for doing an election.

Ex Output:
cumulative voting


Ex Input:
a releaser is a stimulus from one animal to another, which causes a particular response.

Ex Output:
releaser


Ex Input:
eduardo "eddie" gory guerrero yañez (october 9, 1967 – november 13, 2005) better known as eddie guerrero, was an american professional wrestler from a legendary mexican wrestling family.

Ex Output:

eddie guerrero