You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2-cyano-9-oxoindeno[1,2-b]pyrazin-3-yl)cyanamide;ethyl 2-cyano-2-(2-cyano-9-hydroxyindeno[1,2-b]pyrazin-3-ylidene)acetate;9-nitroso-1H-indeno[1,2-b]pyrazine-2,3-dicarbonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C43H20N14O5
assistant