Sorted sequences

A group of students wishes to separate a set of numbers into two sorted lists using stacks and queues. The steps of the developed algorithm are as follows: Let there be an empty queue, say $Q$, and an empty stack, say $S$. - If $Q$ is empty and $S$ is empty, then enqueue the first element $x$ into $Q$. - For the insertion of each element $x$ (other than first element), the following sequential p