You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(9S)-7-bromo-9-(2-hydroxy-4,4-dimethyl-6-oxocyclohexen-1-yl)-3,3-dimethyl-4,9-dihydro-2H-xanthen-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H25BrO4
assistant