You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (E)-3-[3-chloro-5-[5-(hydroxymethyl)-1,3,4-oxadiazol-2-yl]pyridin-2-yl]-N-(3-chloro-4-methylphenyl)but-2-enamide by IUPAC nomenclature, provide its molecular formula.
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C19H16Cl2N4O3
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