class ListNode {

int val;

ListNode next;

ListNode(int x) {

val = x;

next = null;

}

}

public class Solution {

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

// Start typing your Java solution below

// DO NOT write main() function

if(l1 == null) return l2;

if(l2 == null) return l1;

int sum = 0;

int carry = 0;

sum = l1.val + l2.val + carry;

carry = sum / 10;

ListNode result = new ListNode(sum % 10);

l1 = l1.next; l2 = l2.next;

ListNode cur = result;

while(l1 != null && l2 != null){

sum = l1.val + l2.val + carry;

cur.next = new ListNode(sum % 10);

cur = cur.next;

carry = sum /10;

l1 = l1.next; l2 = l2.next;

}

while(l1 != null){

sum = l1.val + carry;

cur.next = new ListNode(sum % 10);

cur = cur.next;

carry = sum /10;

l1 = l1.next;

}

while(l2 != null){

sum = l2.val + carry;

cur.next = new ListNode(sum % 10);

cur = cur.next;

carry = sum /10;

l2 = l2.next;

}

if(carry != 0){

cur.next = new ListNode(carry);

}

return result;

}

public static void main(String[] args) {

// TODO Auto-generated method stub

}

}