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.

Input: Consider Input: Clinical assessment of norepinephrine transporter blockade through biochemical and pharmacological profiles.

Output: norepinephrine


Input: Consider Input: Aripiprazole acts as a selective dopamine D2 receptor partial agonist.

Output: dopamine


Input: Consider Input: Ergovaline binding and activation of D2 dopamine receptors in GH4ZR7 cells.


Output: dopamine