You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-[[4-[[2-bromo-5-(trifluoromethyl)phenyl]sulfonylamino]phenyl]methyl]-3-pyridin-4-ylurea into molecular formula.
user
C20H16BrF3N4O3S
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