You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (2E,4E)-2-cyano-N-[(3,4-dihydroxyphenyl)methyl]-5-(4-hydroxy-3,4-dimethoxycyclohexa-1,5-dien-1-yl)penta-2,4-dienamide by IUPAC nomenclature, provide its molecular formula.
user
C21H22N2O6
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