You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-3-(3,4-dichlorophenyl)-1-(2-methylphenyl)-2,5,6,7-tetrahydroimidazo[2,1-b][1,3]thiazin-4-ium-3-ol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H19Cl2N2OS+
assistant