Axe

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace FifthExcercise
{
    class Program
    {
        static void Main(string[] args)
        {
            int size = int.Parse(Console.ReadLine());

            string singleRowToFormat = "{0}*{1}*{2}";

            char dash = '-';
            char asterisk = '*';

            int figureWidth = size * 5;

            int countOfLeftSymbols = size * 3;
            int countOfMiddleSymbols = 0;
            int countOfRightSymbols = figureWidth - (countOfLeftSymbols + 2);

            string leftPart = string.Empty;
            string middlePart = string.Empty;
            string rightPart = string.Empty;

            // first part
            for (int currentRow = 0; currentRow < size; currentRow++)
            {
                leftPart = new string(dash, countOfLeftSymbols);
                middlePart = new string(dash, currentRow);
                rightPart = new string(dash, countOfRightSymbols--);

                countOfMiddleSymbols = currentRow;

                Console.WriteLine(singleRowToFormat, leftPart, middlePart, rightPart);
            }

            int middleAndBottomPartRows = size / 2;

            // second part
            countOfRightSymbols = countOfMiddleSymbols;
            for (int currentRow = 0; currentRow < middleAndBottomPartRows; currentRow++)
            {
                leftPart = new string(asterisk, countOfLeftSymbols);
                middlePart = new string(dash, countOfMiddleSymbols);
                rightPart = new string(dash, countOfRightSymbols);

                Console.WriteLine(singleRowToFormat, leftPart, middlePart, rightPart);
            }

            // bottom part
            for (int currentRow = 1; currentRow <= middleAndBottomPartRows; currentRow++)
            {
                char middleSymbol = currentRow == middleAndBottomPartRows ? asterisk : dash;

                leftPart = new string(dash, countOfLeftSymbols--);
                middlePart = new string(middleSymbol, countOfMiddleSymbols);
                rightPart = new string(dash, countOfRightSymbols--);

                countOfMiddleSymbols += 2;

                Console.WriteLine(singleRowToFormat, leftPart, middlePart, rightPart);
            }
        }
    }
}