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.

Ex Input:
Selective inhibition of cyclooxygenase 2 spares renal function and prostaglandin synthesis in cirrhotic rats with ascites.

Ex Output:
prostaglandin


Ex Input:
Transdermal selegiline for the treatment of major depressive disorder.

Ex Output:
selegiline


Ex Input:
Effect of chronic renal failure on arginase and argininosuccinate synthetase expression.

Ex Output:

argininosuccinate