You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R,3aR,8S,11bR)-3-[(2R,5R)-5,6-dimethylhept-3-en-2-yl]-3a,6-dimethyl-1,2,3,4,5,7,8,9,10,11b-decahydrocyclopenta[a]anthracen-8-ol is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H42O
assistant