Add Two Numbers Represented by Linked Lists in Reverse Order

amazon You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself. For example, input: (2 -> 4 -> 3) + (5 -> 6 -> 4) output: 7 -> 0 -> 8, because 342 + 465 = 807. Example Input 2 4 3 5 6 4