using System;

public class Program

{

    public static void Main()

    {

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

        int firstStars = 1;

        if (n % 2 == 0) firstStars = 2;

​

​

​

            for (int row = 0; row < (n + 1) / 2; row++)

            {

​

            Console.WriteLine("{0}{1}{0}",

            new string('_', (n - firstStars * (row + 1))/2),

            new string('*', firstStars + (row  )));

    }

    } }

​