You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R,3aS,6R,9aS)-3,5,6-trimethyl-9-methylidene-2,3a,6,7,8,9a-hexahydro-1H-cyclopenta[8]annulen-3-ol is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H24O
assistant