title: Search max value between 2 AVL nodes
body: <p>I have an <code>AVL tree</code> while each node consists of:</p>
  
  <ul>
  <li>Key</li>
  <li>Value</li>
  </ul>
  
  <p>The <code>AVL tree</code> is ordered by the <strong>keys</strong>.</p>
  
  <p>So if I got 2 keys and now I want to find the maximum <strong>value</strong> between those 2 keys.
  I've tried adding additional information to each node like the max value in the left subtree and same for the right subtree but I can't get the right algorithm without "losing" some nodes between.</p>
  
  <p><strong>Complexity time:</strong> <em>O(log n) worst case</em>.</p>