Getting a matrix to a vector

Hi

For 1-dimensional element method analysis of a multi-layered  soil system I need a vector that has value 1 at

each node which is connecting two soil layers and 0 in every other node.

The number of nodes in total is n and the number of soil layers is m.

As attached is a sheet with my tries and with explonations about what I'm trying to achieve.

My solution makes now a matrix with correct amount of nodes and value of 1 at each node that connects two layers,

but it forms a matrix with m columns,

and I don't know how to combine the columns into a single vector.

Thank you for your help.