You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(2R,3S,4S,5R)-5-[(2S,4R)-2,5-dihydroxy-4-methylpentyl]-3,4-dihydroxyoxolan-2-yl]-4,5-dihydroxy-6-[2,3,4,5-tetrahydroxy-6-(1,2,4,5-tetrahydroxypentyl)oxan-2-yl]hexan-3-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H48O17
assistant