Find the values of $K,$ that will make the following system closed loop stable?

$G_m=1$

$G_c=K_c$

$Gv=\frac{1}{s+0\mathrm{.}5}$

$Gp=\frac{2s+1}{s-1}$

$G_L=\frac{3}{(s+1{)}^3}$