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: Birth may be followed by a period of parental care of the offspring.
Example Output: birth baby.

Example Input: Fact: a plant requires photosynthesis to grow.
Example Output: bamboo plant.

Example Input: Fact: Plants use unsaturated fatty acids to store energy.
Example Output:
energy comes from sunlight.