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:
the nepal bhasa wikipedia is the nepal bhasa-language edition of wikipedia.

Ex Output:
nepal bhasa wikipedia


Ex Input:
venice is a city in italy.

Ex Output:
venice


Ex Input:
rupert thorne is a fictional batman character, who is the crime boss of batman.

Ex Output:

rupert thorne