You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3-oxo-4H-[1,2,4]triazino[3,2-a]isoquinoline-1,5-diium-1-yl) ethanesulfonate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C13H13N3O4S+2
assistant