You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8,9-dimethoxy-3,8-dimethyl-2-(2-methylpyridin-4-yl)-5,6-dihydro-1H-pyrrolo[2,1-a]isoquinoline-1-carbonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H25N3O2
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