package main

// 1用于入  2用于pop时暂存数据
var stack1 [] int
var stack2 [] int

func Push(node int) {
    stack1 = append(stack1, node)
}

func Pop() int{
    if len(stack1) == 0 {
        return 0
    }
    
    
    for i := len(stack1)-1; i > 0; i-- {
        stack2 = append(stack2, stack1[i])
    }
    
    res := stack1[0]
    stack1 = stack1[0:0]
    
    for i := len(stack2)-1; i >= 0; i-- {
        stack1 = append(stack1, stack2[i])
    }
    stack2 = stack2[0:0]
    return res
    
}