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 4-(1,2,3,4,4a,5,6,7,8,8a-decahydroisoquinolin-3-yl)-3-[(3,5-difluorophenyl)methyl]-4-hydroxybutanamide .
user
C20H28F2N2O2
assistant