You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(3-cyano-4,5,6,7-tetrahydro-1-benzothiophen-2-yl)-2-(4-oxo-1,2,3-benzotriazin-3-yl)butanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H19N5O2S
assistant