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 (4aS,6aR,10aR)-6-benzyl-4a,6a,7,8,9,10-hexahydro-4H-pyrido[4,3-c]indole-1,3,5-trione .
user
C18H20N2O3
assistant