You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7,7-dimethyl-2-piperidin-1-yl-5,8-dihydropyrano[4,3-b]pyridin-1-ium-3-carbonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H22N3O+
assistant