You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-(4-chlorobenzoyl)-5,5-dimethyl-1'-[(2-methylphenyl)methyl]spiro[1,3-thiazolidine-2,3'-indole]-2'-one into its molecular formula.
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C27H25ClN2O2S
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