Wall boundary line without using room boundary

I want to get the wall boundary without using the Room.CoreBoundary node.
There are no room labels in the model. But the output must be the same as the output of the Room.CoreBoundary node.
Can someone help me?

Hi, simply select the walls and use Element.GetLocation to get the curves.
You can then join them in a polycurve, or print them as detail curve in your view.