Given an array arr[], its starting position l and its ending position r. Sort the array using merge sort algorithm.
Example 1:

Input:
N = 5
arr[] = {4 1 3 9 7}
Output:
1 3 4 7 9

Example 2:

Input:
N = 10
arr[] = {10 9 8 7 6 5 4 3 2 1}
Output:
1 2 3 4 5 6 7 8 9 10

Constraints:
1 <= N <= 10⁵
1 <= arr[i] <= 10³