Given two linked lists, your task is to complete the function makeUnion(), that returns the union of two linked lists. This union should include all the distinct elements only.

Example 1:

Input:
L1 = 9->6->4->2->3->8
L2 = 1->2->8->6->2
Output: 1 2 3 4 6 8 9

Your Task:
The task is to complete the function makeUnion() which makes the union of the given two lists and returns the head of the new list.

Note: The new list formed should be in non-decreasing order.

Expected Time Complexity: O(N * Log(N))
Expected Auxiliary Space: O(N)

Constraints:
1<size of the linked lists<=5000