You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-(3,4-dichlorobenzoyl)piperazin-1-yl]-2-[(4R)-4-(2-methylphenyl)-6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl]ethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H27Cl2N3O2S
assistant