You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[(4S,5S)-5-(4-chlorophenyl)-5-(2-fluoropyridin-4-yl)-4-methyl-1,4-dihydroimidazol-2-yl]-1-ethylpyridin-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H20ClFN4O
assistant