You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,9R)-3,10-dihydroxy-3-methoxy-17-methyl-17-azatetracyclo[7.5.3.01,10.02,7]heptadeca-4,6-dien-13-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H25NO4
assistant