# -*- coding:utf-8 -*-
class Solution:
    def __init__(self):#初始化车道
        self.stack = []

    def push(self, node):
        # write code here
        self.stack += [node]
    def pop(self):
        # write code here
        self.stack.pop()
    def top(self):
        # write code here
        return self.stack[-1]
    def min(self):
        # write code here
        return min(self.stack)