You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (1-benzyl-2-methylindol-3-yl)-[(2R)-1-methylsulfonylspiro[2H-indole-3,4'-piperidine]-2-yl]methanone into its molecular formula.
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C30H31N3O3S
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