You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule [2-[4-(dimethylamino)-6-methyl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-2-yl]piperidin-1-yl]-pyridin-2-ylmethanone ?
user
C21H28N6O
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