[maxmsp] Swapping #s In A List

I have a list of numbers:

12345

I need max to swap the first and second as well as the third and fourth numbers, then swap the second and third and the fourth and fifth. Like so:

12345
changes to
21435
which then changes to
25153

 and so on...

It's a pretty basic question, but I am new to the program and would take any advice possible. I need Max to cycle through these changes until it recreates the original list.

Any help?

Thanks,

joseph