You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-bromo-2-[(E)-2-(4-chlorophenyl)ethenyl]-N-[4-(4-methylpiperazin-1-yl)butyl]-3H-indene-1-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H31BrClN3O
assistant