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: henan is a province of the people's republic of china.
Example Output: henan

Example Input: a dandelion is a flower.
Example Output: dandelion

Example Input: the pothohar plateau (also spelled pothwar, potwar or potohar) is a plateau in punjab, pakistan.
Example Output:
pothohar plateau