You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
16-methoxy-5,7-dioxa-13-azoniapentacyclo[11.8.0.02,10.04,8.015,20]henicosa-2,4(8),9,14,16,18,20-heptaene-11,17-diol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H18NO5+
assistant