For every positive integer n, describe a stack of n pancakes that requires (n) flips to sort.

Suppose you are given a stack of n pancakes of different sizes. You want to sort the pancakes so that smaller pancakes are on top of larger pancakes The only operation you can perform is a flip-insert a spatula under the top k pancakes, for some integer k between 1 and n, and flip them all over. Figure 1.17. Flipping the top four pancakes