You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[11-[4-(dimethylamino)pyridin-1-ium-1-yl]undecyl]-N,N-dimethylpyridin-1-ium-4-amine;dibromide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C25H42Br2N4
assistant