Add two numbers

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.

Class Node:
    data (int)
    next (Node)

Input Format

First Parameter - Node l1

Second Parameter - Node l2

Output Format

Return the head of the list which has sum of both the lists.

Example 1 :

Input :
   l1 = 2 4 3 
   l2 = 5 6 4
Output : 
   7 0 8
Explanation :
    243 
  + 564 
=   708  (adding left to right)

Example 2 :

Input :
    l1 = 9 9 9 9 9 9 9 
    l2 = 9 9 9 9 
Output :
    8 9 9 9 0 0 0 1

Constraints:

• The number of nodes in each linked list is in the range [1, 100].
• 0 <= Node.data <= 9
• It is guaranteed that the list represents a number that does not have leading zeros.