Given a binary tree in which each node element contains a number. Find the maximum possible sum from one leaf node to another.

Input Format:
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
There are multiple test cases. For each test case, the function will be called individually.

Output Format:
For each testcase, in a new line, print the maximum possible sum between two leaf nodes.

Your Task:
Complete the function maxPathSum() that returns the maximum sum from one leaf to another.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(H).
Note: H is the height of the tree and this space is used implicitly for recursion stack.

Constraints:
1 <=T <= 100
3 <= N <= 10⁴
-1000 <= Data on Node <= 1000

Example:
Input:
2
3 4 5 -10 4
-15 5 6 -8 1 3 9 2 -3 N N N N N 0 N N N N 4 -1 N N 10 N

Output:
16
27

Explanation:
Testcase 2: The maximum possible sum from one leaf node to another is (3 + 6 + 9 + 0 + -1 + 10 = 27)

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