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What is the molecular formula of the molecule identified by (3S,3'aS,8'aR,8'bS)-6-chloro-7-methyl-2'-(4-nitrophenyl)spiro[1H-indole-3,4'-3a,6,7,8,8a,8b-hexahydropyrrolo[3,4-a]pyrrolizine]-1',2,3'-trione ?
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C23H19ClN4O5
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