You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 1-[(4-chlorophenyl)-(1-methylimidazol-2-yl)methyl]-3-[[3-(trifluoromethyl)phenyl]methyl]urea .
user
C20H18ClF3N4O
assistant