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.

Q: william frederick "buffalo bill" cody (february 26, 1846 – january 10, 1917) was an american soldier, bison hunter and showman.

A: buffalo bill
****
Q: mrs. hugh hammersley is an oil painting by john singer sargent.

A: mrs. hugh hammersley
****
Q: a hospital ship is a big boat which is built to cure patients.

A:
hospital ship
****