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.
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Question: a hospital ship is a big boat which is built to cure patients.

Answer: hospital ship


Question: sellapan ramanathan (tamil: செல்லப்பன் ராமநாதன்; (july 3, 1924 – august 22, 2016) was the sixth president of the republic of singapore.

Answer: sellapan ramanathan


Question: joan elise sledge (september 13, 1956 – march 10, 2017), better known as joni sledge, was an american singer–songwriter and producer.

Answer:
joni sledge