Leetcode Java Add Two Numbers

Problem:

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
Solution:
Pretty straight forward. 

/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) {
* val = x;
* next = null;
* }
* }
*/
public class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode p = new ListNode(-1);
ListNode head = p;
int carry = 0;
while(l1 != null || l2 !=null || carry == 1){
int currentInt = 0;
if(l1 != null){
currentInt += l1.val;
}
if(l2 != null){
currentInt += l2.val;
}
currentInt += carry;
carry = currentInt/10;
currentInt %= 10;
p.next = new ListNode(currentInt);
p = p.next;
if(l1 != null){
l1 = l1.next;
}
if(l2 != null){
l2 = l2.next;
}
}
return head.next;

}
}