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:
canada day is a national and an official holiday in canada celebrating its anniversary of confederation.

Ex Output:
canada day


Ex Input:
the embassy of russia in copenhagen is the embassy of russia to denmark.

Ex Output:
embassy of russia in copenhagen


Ex Input:
cbsn is an internet television news channel.

Ex Output:

cbsn