You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
I need a molecule that meets the following conditions: The molecule is a p2x7 antagonist. Please represent the molecule in SMILES.
user
O=C(NCC(c1cnc(N2CCNCC2)nc1)N1CCC(F)(F)CC1)c1cccc2nc(NCC3CC3)ccc12
assistant