You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named (3S)-3-(3-oxo-1H-isoindol-2-yl)-N-pyridin-3-yl-3-thiophen-2-ylpropanamide is given. What is its corresponding molecular formula?
user
C20H17N3O2S
assistant