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.

Ex Input:
Fact: sand dunes are formed by the wind transporting and depositing sand.

Ex Output:
sand dune formation desert.


Ex Input:
Fact: All chemical reactions require activation energy to get started.

Ex Output:
activation energy enzyme.


Ex Input:
Fact: an electrical insulator slows the transfer of electricity.

Ex Output:

electrical insulator warm.