You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R,4S)-4-(4-chlorophenyl)-3-[(4-chlorosulfonyl-2-cyanophenoxy)methyl]piperidine-1-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H18Cl2N2O5S
assistant