You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 11,11,12,12-tetramethyl-10-oxa-8-azatricyclo[11.4.0.02,7]heptadeca-1(17),2,4,6,8,13,15-heptaene-9-carbonitrile by IUPAC nomenclature, provide its molecular formula.
user
C20H20N2O
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