You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named N-[1-[(2,6-dichlorophenyl)methyl]pyrazol-4-yl]-3-(1-ethylpyrazol-4-yl)prop-2-enamide by IUPAC nomenclature, provide its molecular formula.
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C18H17Cl2N5O
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