You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,2S,5S,6R,9R,10S,13S,14S)-3,3,4,4,11,11,12,12-octachloro-1,6,7,8,9,14,15,16-octamethylpentacyclo[12.2.1.16,9.02,13.05,10]octadeca-7,15-diene-17,18-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H28Cl8O2
assistant