You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[3-(5-amino-3,6,6-trimethyl-1,1-dioxo-2H-1,4-thiazin-3-yl)-4-fluorophenyl]-5-bromo-3H-isoindol-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H21BrFN3O3S
assistant