You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)-4-oxo-N-[3-(4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)propyl]butanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H27N3O2S2
assistant