You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 11-methyl-5-naphthalen-1-yl-10H-cyclohepta[b]naphthalene;1-[2-(4-phenylphenyl)ethyl]naphthalene by IUPAC nomenclature, provide its molecular formula.
user
C50H40
assistant