Given a binary tree, Your task is to complete the function largestBst that returns the size of the largest subtree which is also a Binary Search Tree (BST). If the whole Binary Tree is BST, then return the size of the whole tree.

Input:

The first line of input contains the number of test cases T. For each test case, there will be only a single line of input which is a string representing the tree as described below: 

1. The values in the string are in the order of level order traversal of the tree where, numbers denote node values, and a character “N” denotes NULL child.

2. For example:
    
   For the above tree, the string will be: 1 2 3 N N 4 6 N 5 N N 7 N

Output:
The function should return the size of the max subtree which is also the BST.

Your Task:
This is a function problem. You don't have to take any input. Just complete the function largestBst() that takes a node as a parameter and return the size of the max subtree which is also the BST.

Constraints:
1 <=T <= 10
1 <= Number of nodes <= 100000
1 <= Data of a node <= 1000000

Example:
Input
2
1 4 4 6 8
6 6 3 N 2 9 3 N 8 8 2

Output
1
2

** For More Input/Output Examples Use 'Expected Output' option **