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 (6aR,9R)-7-methyl-6-propyl-5,5a,6,6a,8,9-hexahydro-4H-indolo[4,3-fg]quinoline-9-carboxylic acid .
user
C19H24N2O2
assistant