problem 3 - hourglass

using System;


class Program
{
    static void Main(string[] args)
    {
        int height = int.Parse(Console.ReadLine());
        int lowerRow = 0;
        for (int i = 0; i < height; i++)
        {
            // height = 7
            if (i < height / 2 + 1)
            {
                // upper half of hourglass
                Console.Write(new string('.', i));
                Console.Write(new string('*', height - 2 * i));
                Console.Write(new string('.', i));
                // 0, 1, ... height / 2
            }
            else
            {
                lowerRow++; // 1,2,3...
                Console.Write(new string('.', height / 2 - lowerRow));
                Console.Write(new string('*', 1 + lowerRow * 2));
                Console.Write(new string('.', height / 2 - lowerRow));
                // height / 2 - 1, height / 2 - 2... 0
            }
            Console.WriteLine();
        }
    }
}