You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (2S,4S,5R,8S,9S,11S,14S,15S)-9,11-dihydroxy-4,8,13,13,15-pentamethyl-12-oxapentacyclo[7.7.0.01,5.02,14.011,15]hexadecane-10,16-dione is given. What is its corresponding molecular formula?
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C20H28O5
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