You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (8'S,9'S,10'R,13'S,14'S)-4',4',10',13'-tetramethylspiro[1,3-dioxolane-2,3'-2,7,8,9,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthrene] by IUPAC nomenclature, provide its molecular formula.
user
C23H36O2
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