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 (4a-hydroxy-1,3,4,5,6,7,8,8a-octahydroisoquinolin-2-yl)-(4-chloro-2-hydroxyphenyl)methanone .
user
C16H20ClNO3
assistant