How to do the same in 3ds max?

Question

3D

https://www.youtube.com/watch?v=Xj8Klx7cfY0&t=462s
In this video, a person at 1.10 selects edges and somehow pulls out new ones. That is, if I try to do this, then I will also have the number of ribs, and he will have new ones. Tried to do the same, pressed Alt Shift Ctrl does not work.
I hope I explained clearly.

Answer 1

You first need to delete the polygon from the end, and then select the edges and extrude them through shift. If two polygons go from the edge, then it will not stretch. I hope I explained clearly