You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (4aR,8aR)-2-[(3-methylquinoxalin-2-yl)methyl]-7-methylsulfonyl-3,4,5,6,8,8a-hexahydro-1H-2,7-naphthyridin-4a-ol .
user
C19H26N4O3S
assistant