You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4-chloro-2-fluorophenyl)-2-[5-[cyclohexyl(methyl)sulfamoyl]pyridin-2-yl]sulfanylpropanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H25ClFN3O3S2
assistant