You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (13Z)-spiro[16-oxa-3,9-diazatetracyclo[15.4.0.04,7.05,9]henicosa-1(21),13,17,19-tetraene-11,3'-azetidine]-2,10-dione .
user
C20H23N3O3
assistant