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 1-(4-bromophenyl)-3-(4-chlorophenyl)-5,7-dimethoxytriazolo[1,5-a]pyrimidin-8-ium;tetrafluoroborate .
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C19H15BBrClF4N4O2
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