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 Input:
nellie paulina burgin (july 14, 1930 – september 20, 2014), better known by her stage name polly bergen, was an american actress, singer, television host, and businesswoman.

Ex Output:
polly bergen


Ex Input:
san diego creek is a small northwest-flowing river in orange county, california.

Ex Output:
san diego creek


Ex Input:
jesse helms (october 18, 1921 - july 4, 2008) was a senator from north carolina.

Ex Output:

jesse helms