Mirror Intersection Sum

You are given two sequences A and B. 1. Build a standard BST from sequence A (values smaller than parent go left, else right). 2. Build a 'Mirrored' BST from sequence B: values GREATER than or equal to parent go LEFT, values smaller than parent go RIGHT. Find the sum of all values that exist in both trees at the exact same depth. Example: Input line 1: 10 5 15 Input line 2: 10 15 5 Tree A: root 10 (d0), 5 (d1-left), 15 (d1-right). Tree B: root 10 (d0), 15 (d1-left), 5 (d1-right). Common (depth, value) pairs: (0, 10), (1, 5), (1, 15). Output: 30