You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 5-[[(1S,3aR,4R,5E,12aR)-4-acetyloxy-1-(2-hydroxypropan-2-yl)-3a-methyl-10-methylidene-9-oxo-2,3,4,7,8,11,12,12a-octahydro-1H-cyclopenta[11]annulen-6-yl]methoxy]-3-hydroxy-3-methyl-5-oxopentanoic acid by IUPAC nomenclature, provide its molecular formula.
user
C28H42O9
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