You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (6E)-3-(dimethylamino)-6-[3-[4-(dimethylamino)-2-hydroxyphenyl]-2-hydroxy-4-oxocyclobut-2-en-1-ylidene]cyclohexa-2,4-dien-1-one into molecular formula.
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C20H20N2O4
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