/* Write an application that prompts the user to enter the size of the side of a square, then displays a hollow square of that size made of asterisks. 

Your application should work for squares of all side lengths between 1 and 20.

If the user enters a number less than 1 or greater than 20, your application should display a square of size 1 or 20, respectively.*/

​

​

​

using System;

public class Program

{

    public static void Main()

    {

            Console.WriteLine("Hello World!");

            Console.WriteLine("Enter the size of the side of a square: ");   

            int side = Convert.ToInt16(Console.ReadLine());

        while(side<1 || side>20){   

            Console.WriteLine("Please enter a number between 1 and 20: ");

            side = Convert.ToInt16(Console.ReadLine());

                         }

            for (int i = 0; i < side; i++)

             {

                 for (int j = 0; j < side; j++)

                 {

                     if (i == 0 || i == side - 1 || j == 0 || j == side - 1)

                     { Console.Write("* "); }

                     else { Console.Write("  "); }

                 }

                Console.WriteLine();

             } 

    }

}