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]: hedi turki (15 may 1922 – 31 march 2019) was a tunisian artist.
[EX A]: hedi turki

[EX Q]: pablo escobar and his brother's school once sent them home because they had no shoes and no money to buy them.
[EX A]: pablo escobar

[EX Q]: bromine dioxide, also known as bromine(iv) oxide, is a chemical compound.
[EX A]:
bromine dioxide