You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(1-hydroxy-1,2-diphenyl-4,5-dihydro-3H-1lambda4-benzothiepin-2-yl)methyl]piperazine is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H32N2OS
assistant