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: cutting down trees has a negative impact on an ecosystem.

Output: cutting down trees.


Input: Consider Input: Fact: Heterotrophs are living things that cannot make their own food.

Output: Heterotrophs.


Input: Consider Input: Fact: Adult echinoderms have radial symmetry.


Output: echinoderm is starfish.