You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[(1S)-1-carboxy-2-[3-[(2,3-difluorophenyl)methyl]imidazol-4-yl]ethyl]amino]-4-methylpentanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H23F2N3O4
assistant