You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[5-[[(4aS,8aR)-3,4,4a,5,6,7,8,8a-octahydro-1H-isoquinolin-2-yl]methyl]-1,2,4-oxadiazol-3-yl]-N-(2-methoxyphenyl)acetamide into its molecular formula.
user
C21H28N4O3
assistant