You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name (4aR,5S)-N-(3-methylbutyl)-8-nitro-1,2,4,4a,5,6-hexahydro-[1,4]oxazino[4,3-a]quinoline-5-carboxamide ?
user
C18H25N3O4
assistant