You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule heptasodium;2-[[1-amino-8-hydroxy-7-[(4-nitro-2-sulfonatophenyl)diazenyl]-4-sulfonato-6H-naphthalen-6-id-2-yl]diazenyl]-5-hydroxy-6-[[4-[(4-sulfonatophenyl)diazenyl]benzene-6-id-1-yl]diazenyl]naphthalene-1,7-disulfonate;sulfur trioxide into molecular formula.
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C38H19N10Na7O25S7
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