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 13-methyl-18-propan-2-yl-1-azapentacyclo[10.7.1.02,7.08,20.014,19]icosa-2,4,6,8(20),9,11,14(19),15,17-nonaene .
user
C23H21N
assistant