You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[7-chloro-1,3-dioxo-2-(pyridin-3-ylmethyl)isoindol-4-yl]-4-propan-2-ylbenzenesulfonamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H20ClN3O4S
assistant