class Solution {
    public ListNode removeNthFromEnd(ListNode head, int n) {
        ListNode start = new ListNode();
        ListNode slow=start, fast=start;
        start.next=head;
        while(n-- +1 >0){
            fast=fast.next;
        }
        
        while(fast!=null){
            fast=fast.next;
            slow=slow.next;
        }
        slow.next=slow.next.next;
        return start.next;
    }
}