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 class Main {
    public static void main(String[] args) {
        int[] a = { 1, 2, 3, 4, 5, 6 };
        int[] b = { 2, 3, 4, 7, 8 };
        int n = a.length + b.length;
        int[] c = new int[n];
        int i = 0;
        int j = 0;
        int k = 0;
        while (i < a.length && j < b.length) {
            if (a[i] < b[j]) {
                c[k] = a[i];
                i++;
            } else {
                c[k] = b[j];
                j++;
            }
            k++;
        }
        while (i < a.length) {
            c[k] = a[i];
            i++;
            k++;
        }
        while (j < b.length) {
            c[k] = b[j];
            j++;
            k++;
        }
        
        for (int x = 0