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: a nest is used for protecting young by birds.
Example Output: bird nest.

Example Input: Fact: a flower 's purpose is to produce seeds.
Example Output: animals seeds.

Example Input: Fact: the looseness of soil has a positive impact on a plant 's roots' growth in that soil.
Example Output:
Plant Roots are.