You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-[[(3S)-3,5-dicyano-4,4-dimethyl-2-oxo-1,3-dihydropyridin-6-yl]sulfanyl]-N-(2-ethoxyphenyl)propanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H22N4O3S
assistant