using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public class Stack

{

    private int maxSize;

    private int top;

    private int[] arr;

    public Stack(int maxSize)

    {

        this.maxSize = maxSize;

        this.top = -1;

        this.arr = new int[maxSize];

    }

    public int GetMaxSize()

    {

        return maxSize;

    }

    public bool IsEmpty()

    {

        return top == -1;

    }

    public bool IsFull()

    {

        return top == maxSize - 1;

    }

    public int Pop()

    {

        if(IsEmpty())

        {

            return 0;

        }

        return arr[top--];

    }

    public void Push(int data)

    {

        if(IsFull())

        {

        }

        arr[++top] = data;

    }

}