You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (6R,7R,10R,13S,17S)-6,7,17-trihydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one into its molecular formula.
user
C19H28O4
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