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: It belongs to the pgd2 receptor antagonist class of molecules.
user
CCOc1ncc(S(=O)(=O)N2CC(C)C(n3nc(CC(=O)O)c4ccc(F)cc43)C2)s1
assistant