You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(1S,2S,13R)-5,7,8,16,18,19-hexamethoxy-6,17,21-trimethyl-12-oxo-11,21-diazapentacyclo[11.7.1.02,11.04,9.015,20]henicosa-4(9),5,7,15(20),16,18-hexaen-10-yl]methyl naphthalene-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C40H44N2O9
assistant