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: Structure-based design, synthesis and evaluation of novel anthra[1,2-d]imidazole-6,11-dione derivatives as telomerase inhibitors and potential for cancer polypharmacology.
Example Output: anthra[1,2-d]imidazole-6,11-dione

Example Input: Effects of silver nanoparticles on the liver and hepatocytes in vitro.
Example Output: silver

Example Input: Phospholipase Cgamma1 negatively regulates growth hormone signalling by forming a ternary complex with Jak2 and protein tyrosine phosphatase-1B.
Example Output:
tyrosine