We considered building a balanced (or full) BST from a sorted array. Assume that the array has n = 2k-1 elements in sorted order. We will insert the array middle element first (as the root), then insert the middle element of the left half, then the middle element of the right half, and so on recursively. Since the array has n elements, the actual work at each level is the insert into the BST. Define the model (using a summation) for the total number of comparisons to insert all the elements into the BST.