You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,3S,4R,5R,6S)-2-[[(1R,2S,4aR,5R,8aR)-5-hydroxy-4a,8-dimethyl-2-propan-2-yl-2,3,4,5,6,8a-hexahydro-1H-naphthalen-1-yl]oxy]-6-(hydroxymethyl)oxane-3,4,5-triol is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H36O7
assistant