You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (3S)-5-chloro-3-[2-(furan-2-yl)-2-oxoethyl]-3-hydroxy-1-[(4-methylphenyl)methyl]indol-2-one is given. What is its corresponding molecular formula?
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C22H18ClNO4
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