In this problem, items are organized in stacks, i$.$e$.,$ a sequence of neighboring tiles in a column with one item per tile. Each stack starts on the floor and can have an arbitrary height. The goal is for Karel to sort the stacks in descending order, as shown below.

Start position End position

Karel starts in the south$-$west corner, facing east, with an empty bag. He needs to end in the same spot, but his orientation doesn$$t matter. There are no walls anywhere inside the map.

Write your solution in sort.c$.$

Hint: For this problem, you probably don$$t want to think about it from a human perspective, where you pick up one stack and put it in the correct position. Instead, have a close look at the start and end situation in the example. What happens to the items in a particular row?