Given two integer arrays inorder and postorder representing the in-order and post-order traversals of a binary tree, construct and return the tree. Output level-order.

Example 1:

Input:
9 3 15 20 7
9 15 7 20 3
Output: 3 9 20 null null 15 7

Input format: Line 1: inorder. Line 2: postorder.

Output format: Level-order traversal.