Hi, here's your problem today. This problem was recently asked by Google:

Given a sorted list, create a height balanced binary search tree, meaning the height differences of each node can only differ by at most 1.

Here's some code to start with:

```
class Node:
def __init__(self, value, left=None, right=None):
self.value = value
self.left = left
self.right = right
def __str__(self):
answer = str(self.value)
if self.left:
answer += str(self.left)
if self.right:
answer += str(self.right)
return answer
def create_height_balanced_bst(nums):
# Fill this in.
tree = create_height_balanced_bst([1, 2, 3, 4, 5, 6, 7, 8])
# 53214768
# (pre-order traversal)
# 5
# / \
# 3 7
# / \ / \
# 2 4 6 8
# /
# 1
```