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 phosphodiesterase inhibitor.
user
C=C(N=CC=C(N)c1c(C(C)C)nn2ccccc12)NC1CCNC1
assistant