You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named [(8S,13S,14S,17S)-3-acetyloxy-13-methyl-6,7,8,12,14,15,16,17-octahydrocyclopenta[a]phenanthren-17-yl] acetate by IUPAC nomenclature, provide its molecular formula.
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C22H26O4
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