You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[(E)-3-(6-bromo-2-oxochromen-3-yl)-3-oxoprop-1-enyl]amino]benzenesulfonamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H13BrN2O5S
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