You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5aR,8S,8aR)-8-phenyl-6-(2-pyrrolidin-1-ylacetyl)-4,5,5a,7,8,8a-hexahydropyrrolo[2,3-f][1,4]oxazepin-3-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H25N3O3
assistant