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.

Input: Consider Input: causality is a way to describe how different events relate to one another.

Output: causality

Input: Consider Input: sceaux-sur-huisne is a commune.

Output: sceaux-sur-huisne

Input: Consider Input: samuel wesley (born bristol, 24 february 1766; died london, 11 october 1837) was an english organist and composer
Output: samuel wesley