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.

import java.util.Arrays;
public class InPlaceMergeSort {

    public static void main(String args[]){
        int arr[] = {2,3,4,5,1};
        int n = arr.length;
        System.out.println("Given Array");
        System.out.println(Arrays.toString(arr));

        sort(arr, 0, n-1);

        System.out.println("\nSorted array");
        System.out.println(Arrays.toString(arr));
    }

    public static void sort(int arr[], int l, int r){
        if (l < r)
        {
            int m = (l+r)/2;
            sort(arr, l, m);
            sort(arr , m+1, r);
            merge(arr, l, m, r);
        }
    }
    static void merge(int arr[], int l, int m, int r){
        int i = 0;
        int j = 0;
        int k = l;