You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-ethoxy-11-methyl-5-methylsulfanyl-8-thia-4,6-diaza-11-azoniatricyclo[7.4.0.02,7]trideca-1(9),2,4,6-tetraene is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H18N3OS2+
assistant