You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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N-[(4-chloro-1-ethylpyrazol-3-yl)methyl]-N-methyl-2-(5-methyl-3-nitropyrazol-1-yl)butanamide is the IUPAC name of a molecule. Please give its molecular formula.
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C15H21ClN6O3
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