You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4aR,10bR)-4-propyl-2,3,4a,5,6,10b-hexahydro-1H-benzo[f]quinoxalin-8-ol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H22N2O
assistant