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 (1R,10S,13S)-16-bromo-10-ethyl-19-hydroxy-5,7,8,18-tetramethoxy-6,17,21-trimethyl-11,21-diazapentacyclo[11.7.1.02,11.04,9.015,20]henicosa-4(9),5,7,15,17,19-hexaene-3,12-dione is given. What is its corresponding molecular formula?
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C28H33BrN2O7
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