Cull naked mesh border vertices with extreme Ymin coordinates

[ilmar_ik]

Hello,
I am experiencing difficulties to create a method to cull all mesh vertices with extreme Ymin coordinates in Rhino workspace on the outside border of the quad mesh surface. cull mesh vertices with extreme Ymin coordinates - discourse.gh (11.7 KB)
P.S. the number of mesh facets (size) is variable
Essentially I want to have a list of points on the mesh border without the culled ones.
Thankful for your advice
Ilja

[HS_Kim]

Like this?

cull mesh vertices with extreme Ymin coordinates - discourse_re.gh (17.3 KB)
Or this?..

cull mesh vertices with extreme Ymin coordinates - discourse_reV2.gh (19.7 KB)

[ilmar_ik]

Thank you @HS_Kim you are very helpful as always!