You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
I give you a description of a molecule, and you need to return one molecule in SMILES that meets the description. The description: The molecule is a anti allergy and belongs to the anti allergic class of molecules.
user
O=c1[nH]nc(-c2nc3ccccc3s2)o1
assistant