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.

Example Input: Adapalene, a new chemical entity with retinoid activity.
Example Output: retinoid

Example Input: CCAAT/Enhancer-binding protein-homologous protein sensitizes to SU5416 by modulating p21 and PI3K/Akt signal pathway in FRO anaplastic thyroid carcinoma cells.
Example Output: SU5416

Example Input: Reinforcement enhancing effects of nicotine via smoking.
Example Output:
nicotine