You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name (3R)-2-[2-[(2S)-3-oxo-4H-1,4-benzothiazin-2-yl]acetyl]-3,4-dihydro-1H-isoquinoline-3-carboxylic acid ?
user
C20H18N2O4S
assistant