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Under IUPAC nomenclature, a molecule named 14-ethyl-6-methyl-2,19-dimethylidene-1,7,13-triazapentacyclo[10.7.1.03,7.08,20.013,18]icosa-3,5,8(20),9,11,14,17-heptaene is given. What is its corresponding molecular formula?
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C22H21N3
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