You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name (3R,3'aS,8'aR,8'bS)-2'-(2,5-dichlorophenyl)-5-fluorospiro[1H-indole-3,4'-3a,6,7,8,8a,8b-hexahydropyrrolo[3,4-a]pyrrolizine]-1',2,3'-trione into its molecular formula.
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C22H16Cl2FN3O3
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