You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule (1-amino-2-methylpropan-2-yl) 4-[(1-ethoxy-1-oxo-3-pyridin-2-ylpropan-2-yl)amino]benzoate into molecular formula.
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C21H27N3O4
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