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: nexon corporation is a korean gaming corporation and developer of online games and mmorpgs.
Example Output: nexon

Example Input: a sawfly is an insect belonging to suborder symphyta of the order hymenoptera.
Example Output: sawfly

Example Input: drillbit taylor is a 2008 comedy movie that was produced by judd apatow and susan arnold and directed by steven brill.
Example Output:
drillbit taylor