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 ethyl 5-methyl-2-[(1S)-1-(1-oxidopyridin-1-ium-2-yl)sulfanylethyl]-4-oxo-3H-thieno[2,3-d]pyrimidine-6-carboxylate .
user
C17H17N3O4S2
assistant