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: noel cobb (21 march 1938 – 2 january 2015) was an american-born british philosopher, psychologist, and author.
Example Output: noel cobb

Example Input: de minimis is a legal term that means that small things do not matter in the law.
Example Output: de minimis

Example Input: s/2004 s 12 is an unnamed moon of saturn.
Example Output:
s/2004 s 12