Intersection of 2 Linked Lists

public class Solution {
    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
        ListNode ptr1 = headA;
        ListNode ptr2 = headB;

        while(ptr1!=ptr2){
            if(ptr1==null){
                ptr1=headB;
            }else{
                ptr1=ptr1.next;
            }

            if(ptr2==null){
                ptr2=headA;
            }else{
                ptr2=ptr2.next;
            }
        }

        return ptr1;
    }
}

Input
8
[4,1,8,4,5]
[5,6,1,8,4,5]
2
3
Output
Intersected at '8'
Expected
Intersected at '8'