In this task, you will be given sentences in which your task is to recognize the name of the drug or medicine. Drugs are substances that change a person's mental or physical state. They can affect how your brain works, how you feel and behave, your understanding, and your senses. Although there might be several correct answers, you need to write one of them.

Example Input: Of the four patients who responded to HU with an increase in total Hb, all reported symptomatic improvement and three have not required further transfusions.
Example Output: HU

Example Input: We present three patients with paradoxical seizures; their serum phenytoin levels were 43.5 mcg/mL, 46.5 mcg/mL and 38.3 mcg/mL.
Example Output: phenytoin

Example Input: Tamoxifen retinopathy.
Example Output:
Tamoxifen