HomeTask.cs

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Int64 a, b, c, d, e, w;
            String u = "";
            String g = "";
            String h = " рублей";
            String j = " рубля";
            String k = " рубль";
            String t = "Итого:";
            String y = "Скидка составила ";
            String l = "Вам необходимо заплатить ";
            String f = "Спасибо за покупку";
            Console.Write("Введите стоимость покупки =>");
            a = Convert.ToInt64(Console.ReadLine());
            if (a >= 10000)
            {
                b = a / 10;
                c = b * 8;
                d = a - c;
                e = c % 10;
                if ((e == 0) || (e > 4))
                    g = h;
                else
                  if (e == 1)
                      g = k;
                  else 
                      g = j;
                w = d % 10;
                if ((w == 0) || (w > 4))
                    u = h;
                else
                    if (w == 1)
                        u = k;
                    else
                        u = j;

                Console.WriteLine(t);
                Console.Write(y);
                Console.Write(d);
                Console.WriteLine(u);
                Console.Write(l);
                Console.Write(c);
                Console.WriteLine(g);
                Console.WriteLine(f);
                Console.ReadLine();
            }
            else
                if (a >= 1000)
                {
                    b = a / 10;
                    c = b * 9;
                    d = a - c;
                    e = c % 10;
                    if ((e == 0) || (e > 4))
                        g = h;
                    else
                        if (e == 1)
                            g = k;
                        else
                            g = j;
                    w = d % 10;
                    if ((w == 0) || (w > 4))
                        u = h;
                    else
                        if (w == 1)
                            u = k;
                        else
                            u = j;

                    Console.WriteLine(t);
                    Console.Write(y);
                    Console.Write(d);
                    Console.WriteLine(u);
                    Console.Write(l);
                    Console.Write(c);
                    Console.WriteLine(g);
                    Console.WriteLine(f);
                    Console.ReadLine();
                }
                else
                {
                    e = a % 10;
                    if ((a >= 10) && (a <= 19))
                        g = h;
                    else
                    if ((e == 0) || (e > 4))
                        g = h;
                    else
                        if (e == 1)
                            g = k;
                        else
                            g = j;
                    Console.WriteLine(t);
                    Console.Write(y);
                    Console.Write("0 рублей");
                    Console.WriteLine(u);
                    Console.Write(l);
                    Console.Write(a);
                    Console.WriteLine(g);
                    Console.WriteLine(f);
                    Console.ReadLine();
                }
        }
    }
}