You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-chloro-3-[4-[4-(6-chloro-4-oxo-2-sulfanylidene-1H-quinazolin-3-yl)phenyl]phenyl]-2-sulfanylidene-1H-quinazolin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H16Cl2N4O2S2
assistant