You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 1-[4-[1-(1,3-dimethylcyclohexa-2,4-dien-1-yl)sulfonyl-3,4-dihydro-2H-pyridin-5-yl]phenyl]ethanone is given. What is its corresponding molecular formula?
user
C21H25NO3S
assistant