You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-(3,8-dinaphthalen-1-ylpyren-1-yl)-4a,9a-dimethyl-9-(2-methylpyridin-4-yl)-1,2,3,4-tetrahydrocarbazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C56H44N2
assistant