You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (1R,4aS,5S,8aR)-5-[(E)-5-hydroxy-3-(hydroxymethyl)pent-3-enyl]-1,4a-dimethyl-6-methylidene-3,4,5,7,8,8a-hexahydro-2H-naphthalene-1-carboxylic acid .
user
C20H32O4
assistant