Given K sorted arrays arranged in form of a matrix. The task is to merge them. You need to complete mergeKArrays() function which takes 2 arguments, an arr[k][k] 2D Matrix containing k sorted arrays and an integer k denoting the number of sorted arrays. The function should return a pointer to the merged sorted arrays.

Input:
The first line of input contains the number of test cases, then T test cases follows. Each test case will contain an integer N denoting the number of sorted arrays. Then in the next line contains all the elements of the array separated by space.

Output:
The output will be the sorted merged array.

User Task:
The task is to complete the function mergeKArrays() which takes two arguments, and returns pointer to the modified array.

Constraints:
1 <= T <= 50
1 <= N <= 10³
1 <= K <= 10

Example:
Input:
1
3
1 2 3 4 5 6 7 8 9 

Output:
1 2 3 4 5 6 7 8 9

Explanation:
Testcase 1:
Above test case has 3 sorted arrays of size 3, 3, 3
arr[][] = [[1, 2, 3],

             [4, 5, 6],

             [7, 8, 9]]
The merged list will be [1, 2, 3, 4, 5, 6, 7, 8, 9].
 

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