You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(2-chlorophenyl)methyl]-2-[2-(2-fluorophenyl)ethylamino]-6-methylpyrimidine-4-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H20ClFN4O
assistant