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For the molecule named (4S)-3-[(1R,2S,3R,8R)-5'-bromo-1'-methyl-2'-oxo-1-phenylspiro[1,2,5,6,7,8-hexahydropyrrolizine-3,3'-indole]-2-carbonyl]-4-phenyl-1,3-oxazolidin-2-one by IUPAC nomenclature, provide its molecular formula.
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C31H28BrN3O4
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