You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-1-[(2-chlorophenyl)methyl]-3-hydroxy-3-[2-(3-nitrophenyl)-2-oxoethyl]indol-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H17ClN2O5
assistant