You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (4E,5R)-4-[(4-chlorophenyl)-hydroxymethylidene]-1-(5-methyl-1,2-oxazol-3-yl)-5-pyridin-3-ylpyrrolidine-2,3-dione by IUPAC nomenclature, provide its molecular formula.
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C20H14ClN3O4
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