You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8-[[4-(3-chlorophenyl)piperazin-1-yl]methyl]-7-ethyl-1,3-dimethyl-5H-purin-3-ium-2,6-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H26ClN6O2+
assistant