You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (2S,3S)-2-(2,3-dihydroxyphenyl)-5,7-dihydroxy-3-[(2R,3R,4R,5S)-3,4,5-trihydroxyoxan-2-yl]oxy-2,3-dihydrochromen-4-one into molecular formula.
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C20H20O11
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