You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7'-(4-ethyl-N-(4-ethylphenyl)anilino)-2'-[(E)-2-(4-ethyl-N-(4-ethylphenyl)anilino)prop-1-enyl]-3'-methylspiro[2-benzofuran-3,4'-chromene]-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C52H50N2O3
assistant