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 7-[[4-[(4-amino-6-sulfonaphthalen-1-yl)diazenyl]-8-hydroxy-6-sulfonaphthalen-1-yl]diazenyl]naphthalene-1,3-disulfonic acid .
user
C30H21N5O13S4
assistant