Let Q denote a queue containing sixteen numbers and S be an empty stack.…

Let Q denote a queue containing sixteen numbers and S be an empty stack.  Head(Q) returns the element at the head of the queue Q without removing it from Q. Similarly, Top(S) returns the element at the top of S without removing it from S. Consider the algorithm given below.

The maximum possible number of iterations of the while loop in the algorithm is ___________ .