You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4aR,8aS)-6-[4-(4-chloro-1,3-dihydroisoindol-2-yl)piperidine-1-carbonyl]-4,4a,5,7,8,8a-hexahydropyrano[3,2-c]pyridin-3-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H28ClN3O3
assistant