You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(1,4-dimethylpiperazin-2-yl)methyl]-2-methyl-3-(9-methyl-9-azabicyclo[3.3.1]nonan-3-yl)guanidine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H36N6
assistant