# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def removeNthFromEnd(self, head, n):
        res=ListNode(0)
        res.next=head
        tmp=res
        for i in range(0,n):
            head=head.next
        while head!=None:
            head=head.next
            tmp=tmp.next
        tmp.next=tmp.next.next
        return res.next