Leetcode Add Two Numbers

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

Difficulty: Medium

/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
int temp = 0;
ListNode res = new ListNode(1);
ListNode curr = res;
while(l1 != null || l2 != null){
int value = temp;
if(l1 != null){
value += l1.val;
l1 = l1.next;
}
if(l2 != null){
value += l2.val;
l2 = l2.next;
}
if(value >= 10){
temp = 1;
value = value - 10;
}
else{
temp = 0;
}
curr.next = new ListNode(value);
curr= curr.next;

}
if(temp == 1){
curr.next = new ListNode(1);
}

return res.next;
}
}