You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance N-[3-(6-bromo-1,3,4,5-tetrahydropyrido[4,3-b]indol-2-yl)-3-oxopropyl]-4-fluorobenzenesulfonamide .
user
C20H19BrFN3O3S
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