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.

[EX Q]: canada day is a national and an official holiday in canada celebrating its anniversary of confederation.
[EX A]: canada day

[EX Q]: mrs. hugh hammersley is an oil painting by john singer sargent.
[EX A]: mrs. hugh hammersley

[EX Q]: stéphane charbonnier (]; 21 august 1967 – 7 january 2015), better known as charb (], was a french cartoonist, journalist, and caricaturist.
[EX A]:
charb