You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-cyclohexyl-N-ethyl-2-[4-[(4-nitrophenyl)methyl]pyridin-1-ium-1-yl]acetamide;chloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H28ClN3O3
assistant