using System;

using System.Linq;

using System.Collections.Generic;

​

public class Stack

{

​

    int[] ele;

    int top;

    int max;

public Stack(int size)

{

    ele=new int[size];

    top=-1;

    max=size;

}

    public void push(int val)

    {

        if(top == max-1)

            Console.WriteLine("overflow");

        else

        {

        top++;

        ele[top]=val;

        }

    }

    public int pop()

    {

        if(top <0)

        {

            Console.WriteLine("underflow"); return -1;

        }

        else

        {

    int temp=ele[top];

        top--;

        return temp;

        }

    }

    public void print()

    {

        ele.ToList().Where((x,i)=>x!=0 && i<=top).ToList().ForEach(x=>Console.Write(x+" "));

    }

}

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var s=new Stack(4);

        s.push(2);

        s.push(16);

        s.push(3);

        s.print();

        Console.WriteLine("Hello World");

        s.pop();

        s.print();

    }

}