You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S)-1-methyl-N-[(1R)-1-(3-methylthiophen-2-yl)-2-phenylethyl]-5-oxopyrrolidine-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H22N2O2S
assistant