Write a Java program modifying the standard Merge Sort algorithm to perform the merging of the two subarrays in-place, without using any additional memory for creating temporary arrays. The goal is to reduce the overall space complexity of the algorithm.

public static void merge(int[] arr, int l, int m, int r)
    {
        int i, j, k;
        int n1 = m - l + 1;
        int n2 =  r - m;
 
        /* create temp arrays */
        int[] L= new int[n1];
        int[] R= new int[n2];
 
        /* Copy data to temp arrays L[] and R[] */
        for (i = 0; i < n1; i++)
            L[i] = arr[l + i];
        for (j = 0; j < n2; j++)
            R[j] = arr[m + 1+ j];
 
        /* Merge the temp arrays back into arr[l..r]*/
        i = 0; // Initial index of first subarray
        j = 0; // Initial index of second subarray
        k = l; // Initial index of merged subarray
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])