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: Characterization of binding sites of a new neurotensin receptor antagonist, [3H]SR 142948A, in the rat brain.

Output: neurotensin


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

Output: dopamine


Input: Consider Input: Biosynthesis of selenocysteine on its tRNA in eukaryotes.


Output: selenocysteine