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:
Inhibition of testicular LDH-X from laboratory animals and man by gossypol and its isomers.

Ex Output:
gossypol


Ex Input:
Use of tranexamic acid for an effective blood conservation strategy after total knee arthroplasty.

Ex Output:
tranexamic acid


Ex Input:
Boron-based inhibitors of acyl protein thioesterases 1 and 2.

Ex Output:

acyl