You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (3R,5R,8S,9S,10R,13S,14S,17S)-17-(hydroxymethyl)-10,13-dimethyl-1,2,3,4,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthrene-3,5-diol by IUPAC nomenclature, provide its molecular formula.
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C20H34O3
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