Add two linkedlist

addlinkedlist.java

public static ListNode sumTwoLinkedLists(ListNode input1, ListNode input2) {
          int carryComponent =0;
    
           ListNode returnHead = new ListNode(0);
           ListNode n1 = input1, n2 = input2, n3=returnHead;
    
           while(n1 != null || n2 != null){
               if(n1 != null){
                 carryComponent += n1.data;
                   n1 = n1.next;
               }
    
               if(n2 != null){
                 carryComponent += n2.data;
                   n2 = n2.next;
               }
    
               n3.next = new ListNode(carryComponent%10);
               n3 = n3.next;
               carryComponent /= 10;
           }
    
           if(carryComponent==1) 
               n3.next=new ListNode(1);
    
           return returnHead.next;      
  }