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 trisodium;5-[[2-methoxy-5-methyl-4-[(4-sulfonatophenyl)diazenyl]anilino]-oxoazaniumyl]-2-[(E)-2-(4-nitro-2-sulfonatophenyl)ethenyl]benzenesulfonate .
user
C28H21N5Na3O13S3+
assistant