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: stalactites are formed by deposition.

Output: deposition sand limestone.


Input: Consider Input: Fact: protein is used to repair cells by the human body.

Output: cells die repair.


Input: Consider Input: Fact: oil is formed by layers of sediment pushing down on decomposing algae.


Output: algae is.