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: sonic firestorm is the second studio album by english power metal band dragonforce released through on may 11, 2004.
Example Output: sonic firestorm

Example Input: kurt julius isselbacher (september 12, 1925 – july 18, 2019) was a german-born american physician and gastroenterologist.
Example Output: kurt julius isselbacher

Example Input: rzhev is a town in tver oblast, russia.
Example Output:
rzhev