You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[3,5-bis(trifluoromethyl)phenyl]-4-(6-pyrrol-1-ylpyridazin-3-yl)piperazine-1-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H18F6N6O
assistant