You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-[[5-(4-bromophenyl)-4-(2-phenylethyl)-1,2,4-triazol-3-yl]sulfanyl]propanenitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H17BrN4S
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