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: burning fossil fuels increases the carbon in the atmosphere.
Example Output: carbon atmosphere.

Example Input: Fact: TRH stimulates the pituitary gland to produce thyroid-stimulating hormone, or TSH.
Example Output: TRH.

Example Input: Fact: Pressure receptors are found mainly in the skin.
Example Output:
Pressure receptors.