You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R,4aS,7S,7aR,12bS)-9-methoxy-1,2,3,4,4a,7,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinolin-7-ol is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H19NO3
assistant