You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(2S,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxypropan-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H26O12
assistant