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]: eric saade (born 29 october 1990 in helsingborg, sweden) is a swedish singer.
[EX A]: eric saade

[EX Q]: mae west (august 17, 1893 – november 22, 1980) was an american actress and movie star.
[EX A]: mae west

[EX Q]: a black powder rocket motor pushes a model rocket using black powder.
[EX A]:
black powder rocket motor