You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(2Z)-2-[[5-[6-[5-[(Z)-[(1Z)-1-(1-cyanoprop-2-ynylidene)-3-oxoinden-2-ylidene]methyl]-3-(2-ethylhexyl)thiophen-2-yl]-4,8-bis(5-hexylthiophen-2-yl)thieno[2,3-f][1]benzothiol-2-yl]-4-(2-ethylhexyl)thiophen-2-yl]methylidene]-3-oxoinden-1-ylidene]propanedinitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C81H79N3O2S6
assistant