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: "canuck" is a slang term for canadian people.
Example Output: canuck

Example Input: the bucket list is a 2007 american comedy-drama movie.
Example Output: the bucket list

Example Input: radio:active (typeset as radio:active) is the fourth album by british pop rock band mcfly.
Example Output:
radio:active