You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[3,5-bis[4-[(6-pyridin-2-ylpyridin-3-yl)amino]phenyl]phenyl]phenyl]-6-pyridin-2-ylpyridin-3-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C54H39N9
assistant