You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-amino-N-[(2,4-dichlorophenyl)methyl]-N-methyl-2-oxo-1,3,4,5-tetrahydro-1-benzazepine-7-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
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C19H19Cl2N3O2
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