You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (8R,9S,10R,13S,14S)-17-acetyl-13-methyl-2,6,7,8,9,10,11,12,14,15-decahydro-1H-cyclopenta[a]phenanthren-3-one into molecular formula.
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C20H26O2
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