You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 4-[[(3aS,6S,6aS)-6a-hydroxy-6-(3-hydroxyocta-1,5-dienyl)-2,3,3a,4,5,6-hexahydro-1H-pentalen-2-yl]oxy]butanoic acid into its molecular formula.
user
C20H32O5
assistant