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.

Input: Consider Input: island of the blue dolphins is an american book written for children by scott o'dell.

Output: island of the blue dolphins


Input: Consider Input: dje, or djerv (Ђ, ђ) is the sixth letter of the serbian cyrillic alphabet, used in the serbian language to represent the sound for need to tell /dʑ/, a palatalisation, similar to the english sound of letter "j" .

Output: dje


Input: Consider Input: "like father, like clown" is the sixth episode of the simpsons third season.


Output: like father, like clown