You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (4aR,9aR)-5-methyl-1-(5-methyl-1,3-oxazole-4-carbonyl)-2,3,4,4a,7,8,9,9a-octahydropyrido[3,2-b]azepin-6-one into its molecular formula.
user
C15H21N3O3
assistant