using System;
public class Program
{
public static void Main()
int size = 0;
Console.Write("Enter square size: ");
size = int.Parse(Console.ReadLine());
if (size > 20)
size = 20;
for (int i = 1; i <= size; i++)
for (int j = 1; j <= size; j++)
if ((i == 1 || i == size || j == 1 || j == size))
Console.Write("* ");
else
Console.Write(" ");
}
Console.WriteLine();