You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-[(2R,6R)-2-cyclopropyl-6-methylmorpholin-4-yl]pyridin-4-yl]-pyridin-3-ylmethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21N3O2
assistant