The house of Santa Claus is an old German drawing game for small children.
You have to draw a house in one line.  
You must not lift your pencil while drawing. You must not repeat a line.

A possible solution for drawing such a house is:

[![enter image description here][1]][1]

The drawings sequence is here: 1->2->4->1->3->4-A5->3->2
 
How can one find out all existing drawing sequences?

  [1]: https://i.sstatic.net/chQyv.png