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 4,11-difluoro-14-azapentacyclo[12.7.0.02,7.08,13.015,20]henicosa-1(21),2(7),3,5,8(13),9,11,15,17,19-decaene .
user
C20H11F2N
assistant