You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-1-(5-bromo-2-methoxyphenyl)-N-[4-(9H-fluoren-9-yl)piperazin-4-ium-1-yl]methanimine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C25H25BrN3O+
assistant