class Node
{
    int data;
    Node left, right;
 
    public Node(int item)
    {
        data = item;
        left = right = null;
    }
}
 
public class ValidBSTOrNot
{
    //Root of the Binary Tree
    Node root;
 
    /* can give min and max value according to your code or
    can write a function to find min and max value of tree. */
 
    /* returns true if given search tree is binary
     search tree (efficient version) */
    boolean isBST()  {
        return isBSTUtil(root, Integer.MIN_VALUE,
                               Integer.MAX_VALUE);
    }
 
    /* Returns true if the given tree is a BST and its
      values are >= min and <= max. */
    boolean isBSTUtil(Node node, int