You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(3,5-dimethylphenyl)-4-(1H-pyrazol-5-yl)-[1,2,4]triazolo[1,5-a]pyrazin-4-ium-2-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H16N7+
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