Trying to extract points of a bunch of curves just for one side

i have made a random floor tower and now i want to have a core for this building , and i want to extract all of the points on one side as i have shown it on the screenshot I’ve provided.
these curves are so jagged ,and they are generated randomly .
can anyone help me please?

next-rotating-floors.3dm (58.2 KB) (19.6 KB)

DUPLICATE THREAD!!! Please don’t do that.