T: Binary Tree node; T.left and T.right: pointers to the left and right children of node T.

Mystery (T: Binary Tree Root Node)

1. if T.left == NULL and T.right == NULL then return 0

2. if T.left != NULL and T.right != NULL then

3. return Larger(Mystery(T.left), Mystery(T.right)) + 1 //Larger(x,y) returns larger of x and y

4. if T.left != NULL then return Mystery(T.left)+1

5. if T.right != NULL then return Mystery(T.right)+1

What does Mystery compute?