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:
stinging nettles ("urtica dioica") are a type of plant which have stinging defensive hairs on the leaves and stems.

Ex Output:
stinging nettle


Ex Input:
nickel creek was an american acoustic musical group.

Ex Output:
nickel creek


Ex Input:
marjorie lord (born 26 july 1918) is an american actress.

Ex Output:

marjorie lord