You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 5,15-dimethyl-2,18-dimethylidene-4,16-dioxa-1-azapentacyclo[10.6.1.03,7.08,19.013,17]nonadeca-3(7),5,8(19),9,11,13(17),14-heptaene .
user
C20H15NO2
assistant