text: 
  
  class TreeNode:
      def __init__(self, val):
          self.val = val
          self.left, self.right = None, None
  
  
  def flip_sideways(node):
  
      if node is None:
          return
  
      # swap
      node.left, node.right = node.right, node.left
  
      if node.left is not None:
          flip_sideways(node.left)
      if node.right is not None:
          flip_sideways(node.right)
  
      return
  
  
  def main():
      root = TreeNode(1)
      root.left = TreeNode(7)
      root.right = TreeNode(9)
      root.left.left = TreeNode(4)
      root.left.right = TreeNode(5)
      root.right.left = TreeNode(2)
      root.right.right = TreeNode(7)
  
      flip_sideways(root)
  
      print(f'{root.right.right.val}')
  
  
  if __name__ == "__main__":
      main()