You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-(2,3-dihydro-1,4-benzodioxin-6-ylmethyl)-N-methyl-4-(6-nitro-2-oxo-1,3-benzoxazol-3-yl)butanamide into molecular formula.
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C21H21N3O7
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