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.

Example Input: Fact: Differentiation is the process by which unspecialized cells become specialized.
Example Output: cell Differentiation.

Example Input: Fact: predicting weather requires studying weater.
Example Output: meteorologists.

Example Input: Fact: when the body is hot , sweat is produced to cool the body.
Example Output:
body heating causes.