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 (9-amino-3-bicyclo[3.3.1]nonanyl)-(1,3,4,6,7,8,9,9a-octahydropyrido[1,2-a]pyrazin-2-yl)methanone .
user
C18H31N3O
assistant