# -*- coding:utf-8 -*-
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
    # 返回ListNode
    def ReverseList(self, pHead):
        # write code here
        head=None
        while pHead :
            #res.append(pHead.val)
            pHead.next,head,pHead=head,pHead,pHead.next
        return head