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 dioxide concentrations in the air have increased over the last decade dramatically.

Output: carbon dioxide CO.


Input: Consider Input: Fact: Muscles can only contract.

Output: contract leg.


Input: Consider Input: Fact: Marine species live mainly in shallow coastal waters.


Output: Marine means.