You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-[[4-[(4-cyano-3-methyl-1-oxo-5H-pyrido[1,2-a]benzimidazol-2-yl)diazenyl]-2,5-dimethylphenyl]diazenyl]benzene-1,4-disulfonic acid .
user
C27H21N7O7S2
assistant