You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named [(8R,9S,10R,13S,14S,17R)-17-acetyl-6-chloro-10,13-dimethyl-1,2,3,8,9,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-17-yl] 2-hydroxyacetate by IUPAC nomenclature, provide its molecular formula.
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C23H31ClO4
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