The stepwise formation of ${{\left[Cu{\left(N{H}_3\right)}_4\right]}^2}^{+}$ is given below:

$C{u}^{2+}+N{H}_3\stackrel{k_1}{\rightleftharpoons }{\left[Cu\left(N{H}_3\right)\right]}^{2+}$

${\left[Cu\left(N{H}_3\right)\right]}^{2+}+N{H}_3\stackrel{k_2}{\rightleftharpoons }{\left[Cu{\left(N{H}_3\right)}_2\right]}^{2+}$

${\left[Cu{\left(N{H}_3\right)}_2\right]}^{2+}+N{H}_3\stackrel{k_3}{\rightleftharpoons }{\left[Cu{\left(N{H}_3\right)}_3\right]}^{2+}$

${\left[Cu{\left(N{H}_3\right)}_3\right]}^{2+}+N{H}_3\stackrel{k_4}{\rightleftharpoons }{\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}$            

The value of stability constants k₁, k₂, k₃ and k₄ are $10^4,1.58*10^3,5*10^{2}and10^2$  respectively.

The overall equilibrium constants for dissociation of ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}isx*10^{-12}.$  The value of x is________ (Rounded off to the nearest integer)