You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-3-[(1-methylindol-3-yl)methyl]-9-methylsulfonyl-2,3-dihydro-1H-carbazol-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H22N2O3S
assistant