#coding:utf-8
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
# 
# @param head ListNode类 
# @return ListNode类
#
class Solution:
    def ReverseList(self , head ):
        # write code here
        pree=None
        cur =head
        while cur:
            temp=cur.next
            cur.next=pree
            pree=cur
            cur=temp
        return pree