You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance [(1R,3aR,3bS,5aS,6S,8aS,8bR,10aR)-1-hydroxy-1-(hydroxymethyl)-3a,5a-dimethyl-3,3b,4,5,6,7,8,8a,8b,9,10,10a-dodecahydro-2H-indeno[5,4-e]inden-6-yl] acetate .
user
C21H34O4
assistant