You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
9-[3-tert-butyl-5-(4-tert-butylpyridin-2-yl)phenyl]-2-(4-tert-butylpyridin-2-yl)-1H-indeno[2,1-b]pyridine is the IUPAC name of a molecule. Please give its molecular formula.
user
C40H43N3
assistant