Generate a Java program to implement Merge Sort algorithm to efficiently sort an array of elements in ascending order.

public class MergeSort {

   public static void sort(int[] a, int n) {
      if (n < 2) {
         return;
      }
      int mid = n / 2;
      int[] l = new int[mid];
      int[] r = new int[n - mid];
 
      for (int i = 0; i < mid; i++) {
         l[i] = a[i];
      }
      for (int i = mid; i < n; i++) {
         r[i - mid] = a[i];
      }
      sort(l, mid);
      sort(r, n - mid);
 
      merge(a, l, r, mid, n - mid);
   }
 
   public static void merge(
      int[] a, int[] l, int[] r, int left, int right) {
      
      int i = 0, j = 0, k = 0;
      while (i < left && j < right) {
         if (l[i] <= r[j]) {
            a