You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 5-bromo-N-[(E)-[5-(4-cyanophenyl)furan-2-yl]methylideneamino]-1-benzofuran-2-carboxamide into its molecular formula.
user
C21H12BrN3O3
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