You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance [(2R,4aS,5R,10bS)-5-(2-fluorophenyl)-9-(trifluoromethyl)-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinolin-2-yl]methanol .
user
C20H19F4NO2
assistant