List Sorting Ascending and Descending

I started with 2 ranges, and created a list of all permutations of the list. I want to sort the list in a unique way. Using the List.sort node sorts it in ascending order, but I want it sorted by ascending order for the first character and descending order of the last character. My list contains Numbers 1-6 a comma and then numbers 1-6 for a total of 36 combinations.

The first set is columns and the second set of numbers is rows.

So close! Just transpose your lists before you flatten.

Thanks, I new I was close and missing something.