You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-bromo-N-[(2S)-2-(4-fluorophenyl)-2-(4-methylpiperazin-1-yl)ethyl]benzenesulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H23BrFN3O2S
assistant