You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(6,6-dimethyl-4-oxo-5,7-dihydro-1,3-benzothiazol-2-yl)-2-(5,6-dimethylthieno[2,3-d]pyrimidin-4-yl)sulfanylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H20N4O2S3
assistant