You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (4Z)-5-(4-ethylphenyl)-4-[hydroxy-(4-methylphenyl)methylidene]-1-[2-(5-methoxy-1H-indol-3-yl)ethyl]pyrrolidine-2,3-dione by IUPAC nomenclature, provide its molecular formula.
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C31H30N2O4
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