You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
10-methyl-3-[3,4,6-trideuterio-5-(trideuteriomethyl)pyridin-2-yl]oxonino[2,3-b]pyridine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H16N2O
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