Data structure in java language ,please i don't have time

Assume that numbers are represented in linked lsits (i.e. the number 567 will be represented in a linked list of three nodes; the first node contains 5, the second node contains 6 and the last node contains 7.

Write a java method that receives the heads of two linked lists representing two numbers and finds the sum list and returns its head.

Assume that the linked list class is ready and called (MyLinkedList) that contains nodes with int data, and next reference. Assume also that the following methods are available on hand: addFirst(), addLast(), addAtIndex(), removeFirst(), removeLast(), removeAtIndex(), size().

Note: You are free to use any data structure (queue, stack, set, map, tree) in your solution.