You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
iodomethane;(1S,2R,17R)-12-methoxy-18-methyl-10-oxa-6,7,18-triazahexacyclo[9.9.1.01,9.02,17.04,8.015,21]henicosa-4(8),5,11,13,15(21)-pentaene The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H24IN3O2
assistant