You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-methoxy-3-methylidene-7-(4-methyl-2,3,6,7-tetrahydroazepin-1-yl)-2,4-dihydroazepine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H22N2O
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