Consider the following reactions (NiS+HNO_ 3 + HCl arrow A+NO+S+H_...

Consider the following reactions (\mathrm{NiS}+\mathrm{HNO}_{3}+ \mathrm{HCl} \rightarrow \mathrm{A}+\mathrm{NO}+\mathrm{S}+\mathrm{H}_{2} \mathrm{O}) $$\begin{aligned}\mathrm{A}+\mathrm{NH}_{4} \mathrm{OH}+\mathrm{H}_{3} \mathrm{C}-\mathrm{C}& =\mathrm{N}-\mathrm{OH}\\ | \\ \mathrm{H}_{3} \mathrm{C}-\mathrm{C}& = \mathrm{N}-\mathrm{OH}\end{aligned}$$ \rightarrow \mathrm{B}+\mathrm{NH} }_{4} \mathrm{Cl}+\mathrm{H}_{2} \mathrm{O} The number of protons that do not involve in hydrogen bonding in the product $B$ is ______.