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 ret kinase inhibitor and is cancer treatment.
user
COC(=O)c1ccc2cc3n(c2c1)C(=O)NCc1c-3c2c(N)ncnc2n1C(C)C
assistant