the binary tree should hold its property that left subtree.val < root.val and right subtree.val > root val.

but, when I submit my algorithm, it goes like this:

```
Runtime ErrorMore Details
Runtime Error Message: Line 23: ValueError: 2 is not in list
Last executed input: [-4,-10,3,-1,7,11,-8,2], [-4,-1,3,-10,11,-8,2,7]
```

actually, the test case does not meet the property .

the postorder is [-4,-1,3,-10,11,-8,2,7] ,so the root is 7.

so in inorder [-4,-10,3,-1,7,11,-8,2], the value on the left of 7 should be smaller than 7 , the value on the right should be bigger than 7.

so I think this case is totally wrong.