$.  0.  If equation $v_{0m+0}=w_{0n}$ has a solution, then $|z_0|=t$, $|z_0|=\frac{0}{0}(cr-st)$ and $z_0z_0<0$.  0.  If equation $v_{0m}=w_{0n+0}$ has a solution, then $|z_0|=s$, $|z_0|=\frac{0}{0}(cr-st)$ and $z_0z_0<0$.  0.  If equation $v_{0m+0}=w_{0n+0}$ has a solution, then $|z_0|=t$, $|z_0|=s$ and $z_0z_0>0$.  