You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-(3-bromobenzoyl)-3-methylpiperazin-1-yl]-2-(4-phenyl-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
C27H28BrN3O2S
assistant