You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-(2,4-dichlorophenyl)sulfonylbutyl]-2-(2-methoxyethyl)-7-methylimidazo[4,5-c]pyridin-4-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H24Cl2N4O3S
assistant