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: an air raid is an attack in which bombs are dropped from aircraft on to a ground or sea target.
Example Output: air raid

Example Input: rougefay is a commune.
Example Output: rougefay

Example Input: aillant-sur-tholon is a commune.
Example Output:
aillant-sur-tholon