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
CCNC(=O)NC1CCC(C(=O)N2CCC(OC(C)c3cc(C(F)(F)F)cc(C(F)(F)F)c3)C(c3ccccc3)C2)CC1
assistant