text: """
  # Perfect Binary Tree (PBT) 
  
  # Description 
  Let's assume that there is a perfect binary tree of a certain height. 
  The leaves of the tree has a linear value of incrementing positive integers starting from one. 
  Each node is filled with an integer in the order of post-order traversal. 
  
  For instance, if we have a PBT of depth 3, the tree will look like:
  
       7
    3    6
  1  2  4  5
  
  
  ## Interesting properties of PBT 
  1) Relationship between the parent and right-child nodes.
  In this arrangement (post-order traversal of a PBT),
  the parent node of the right child node is always +1. In other words,
  the right child node of the parent node is always -1. 
  This is because the right node is always the last one to be visited and we have to move up the depth. 
  
  -------------------------------------------
  """
  