You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (2R,3R,4S,5S,6R)-5-[(2S,3R,4S,5S,6R)-4,6-bis(ethoxymethyl)-3,5-dihydroxyoxan-2-yl]oxy-3-ethoxy-6-(hydroxymethyl)oxane-2,4-diol by IUPAC nomenclature, provide its molecular formula.
user
C19H36O11
assistant