You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[1-oxo-1-(pyridin-2-ylamino)butan-2-yl] 4-(4-chlorophenyl)-2-methyl-1-oxoisoquinoline-3-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H22ClN3O4
assistant