using System;

public class Program

{

    public static void Main()

    {

        int num,x=1;

    Console.WriteLine("please enter number:");

    num=int.Parse(Console.ReadLine());

     while (x<=num*num)

     {

    if(x%2==1)   

    Console.Write("*");

    else 

    Console.Write(" ");  

    if(x%num==0)

    Console.WriteLine();

    x++;

     }

    }

}