You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule [(2-ethyl-4-oxo-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-3-yl)amino]methylidene-dimethylazanium .
user
C15H21N4OS+
assistant