You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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(4Z)-4-[(4-bromo-3-methylphenyl)-hydroxymethylidene]-5-(3-chloro-4-hydroxyphenyl)-1-cyclopentylpyrrolidine-2,3-dione is the IUPAC name of a molecule. Please give its molecular formula.
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C23H21BrClNO4
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