public class Solution
{
	public ListNode addTwoNumbers(ListNode l1,ListNode l2)
	{
	   ListNode ln1=l1,ln2=l2,head=null,node=null;
	   int carry=0,remainder=0,sum=0;
	   head=node=ListNode(0);
	   while(ln1！=null||ln2!=null||carry！=0)
	   {
	   	sum=(ln1!=null?ln1.val:0)+(ln2!=null?ln2.val:0)+carry;
	   	carry=sum/10;
	   	remainder=sum%10;
	   	node=node.next=ListNode(remainder);
	   	ln1=(ln1!=null?ln1.next:0);
	   	ln2=(ln2!=null?ln2.next:0);
	   }
	   return head.next;
	}
}