You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(1S)-1-(4-chlorophenyl)ethyl]-3-[[3-[(4-fluorophenyl)methyl]imidazo[4,5-b]pyridin-2-yl]methyl]urea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H21ClFN5O
assistant