You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-amino-3-methyl-N-[2-oxo-2-[(1-phenylbenzimidazol-2-yl)amino]ethyl]butanamide;hydrochloride The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H24ClN5O2
assistant