In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.

Input: Consider Input: Oxysterol generation and liver X receptor-dependent reverse cholesterol transport: not all roads lead to Rome.

Output: cholesterol

Input: Consider Input: Nuclear receptors in bile acid metabolism.

Output: bile acid

Input: Consider Input: Hypoxemia associated with cimetidine therapy in a newborn infant.
Output: cimetidine