In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.

Input: Consider Input: Fact: Carbon cycles quickly between organisms and the atmosphere.

Output: atmosphere air.


Input: Consider Input: Fact: when electricity flows to a light bulb , the light bulb will turn on.

Output: electricity electrons.


Input: Consider Input: Fact: Annelids are worms such as the familiar earthworm.


Output: annelid.