You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[1-[[6-(chloromethyl)pyridin-2-yl]methyl]indol-3-yl]-4-(1-methylindol-2-yl)furan-2,5-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H20ClN3O3
assistant