You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
9-[4-(2,6-dimethylphenyl)-3,5-dimethylpyridin-2-yl]-2-[3-[5-[3-[9-[4-(2,6-dimethylphenyl)-3,5-dimethylpyridin-2-yl]carbazol-2-yl]oxyphenyl]pyrazin-2-yl]phenoxy]carbazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C70H56N6O2
assistant