You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named methyl (1S,2R,4R,5R,7R,8E,10R,11S,12R)-10-acetyloxy-11-[(2S,3S)-2,3-dimethyloxirane-2-carbonyl]oxy-4-methyl-13-methylidene-14-oxo-3,6,15-trioxatetracyclo[10.3.0.02,4.05,7]pentadec-8-ene-9-carboxylate by IUPAC nomenclature, provide its molecular formula.
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C23H26O11
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