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 5-amino-3-[(Z)-2-(3-bromo-4,5-dimethoxyphenyl)-1-cyanoethenyl]-1-phenylpyrazole-4-carbonitrile into molecular formula.
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C21H16BrN5O2
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