You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[4-chloro-2-[(5-chloropyridin-2-yl)carbamoyl]phenyl]-4-fluoro-3-(trifluoromethyl)benzamide into molecular formula.
user
C20H11Cl2F4N3O2
assistant