class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        //cout << l1->next->next->val <<endl; //get third digit
        int carry=0;
        //ListNode* sum;
        ListNode* A=new ListNode(0);

        while(l1 || l2 || carry){
            int sum=0;
            if(l1 != NULL){
                sum += l1->val;
                l1 = l1->next;
            }
            if(l2 != NULL){
                sum += l2->val;
                l2 = l2->next;
            }
            sum += carry;
            carry = sum/10;
            A->next = new ListNode(sum%10);
            A = A->next;

        }

        return A->next;
    }
};