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: Management of psoriasis: the position of retinoid drugs.
Example Output: retinoid

Example Input: Cholestatic effect of epigallocatechin gallate in rats is mediated via decreased expression of Mrp2.
Example Output: epigallocatechin gallate

Example Input: Stable and high-rate overcharge protection for rechargeable lithium batteries.
Example Output:
lithium