You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3R,4S,5S,6R)-2-[(2S,3S,4S,5R)-3,4-dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol;2-ethyl-2-(hydroxymethyl)propane-1,3-diol is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H36O14
assistant