You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-benzyl-4-[2-[4-(2,3-dimethylphenyl)piperazin-1-yl]-2-oxoethoxy]benzenesulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H31N3O4S
assistant