You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 3-[6-[(4-amino-3-ethylpiperidin-1-yl)methyl]-3-oxo-1H-isoindol-2-yl]piperidine-2,6-dione ?
user
C21H28N4O3
assistant