You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (2R,3R,4R,5S,6R)-2-(9-hydroxy-5,11-dimethyl-6H-pyrido[4,3-b]carbazol-2-ium-2-yl)-6-(hydroxymethyl)oxane-3,4,5-triol;bromide .
user
C23H25BrN2O6
assistant