You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (3S,3aR,4aR,8aR,9aR)-3,8a-dimethyl-5-methylidene-3,3a,4,4a,9,9a-hexahydrobenzo[f][1]benzofuran-2,6-dione into its molecular formula.
user
C15H18O3
assistant