You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,4S,5S,6R)-1,8-bis(4-fluorophenyl)octa-1,7-diene-2,3,4,5,6,7-hexol is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20F2O6
assistant