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.

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

Output: sellapan ramanathan


Input: Consider Input: nelsan ellis (november 30, 1977 – july 8, 2017) was an american actor and playwright.

Output: nelsan ellis


Input: Consider Input: the sahel is a narrow belt of land in west africa.


Output: sahel