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: rupert thorne is a fictional batman character, who is the crime boss of batman.
Example Output: rupert thorne

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: the royal ontario museum or rom, is a major museum for culture and natural history in the city of toronto, ontario, canada.
Example Output:
royal ontario museum