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 tachykinin antagonist.
user
O=C(c1cc(C(F)(F)F)ccc1C(F)(F)F)N1CCN(Cc2ccccc2)CC1Cc1c[nH]c2ccccc12
assistant