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: Migrants typically travel long distances.

Ex Output:
long distances travel time.

Ex Input:
Fact: changes in the pH of soil can cause plants to die.

Ex Output:
change ph soil.

Ex Input:
Fact: Grasses supply most of the food consumed by people worldwide.

Ex Output:
grasses are plants.