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:
regent's canal is a canal in england.

Ex Output:
regent's canal


Ex Input:
be careful with my heart is a philippine television drama series.

Ex Output:
be careful with my heart


Ex Input:
theoxena scissaria is a species of moth.

Ex Output:

theoxena scissaria