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 2,6-difluoro-N-[2-oxo-2-(5-pyridin-4-yl-2,3-dihydroindol-1-yl)ethyl]benzenesulfonamide .
user
C21H17F2N3O3S
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