You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(3,4-dihydroxyphenyl)-3-[(2S,5S)-3,4-dihydroxy-5-[(2R,5S)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-[[(2R,5R)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxymethyl]oxan-2-yl]oxy-5,7-dihydroxychromen-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C33H40O21
assistant