static void Main(string[] args)
        {
            Console.WriteLine("Введите N");
            int N = inputInt();
            int a, b;
            summaRada(N, out a, out b);
            Display(a, b);
            Console.ReadKey();
        }

       static void summaRada(int N, out int summA, out int summB)
       {
            summA = -1;
            summB = 1;

            if( N <= 2 )
            {
                summA = 1;
                summB = 1;
                return;
            }

            for (int i = 2; i < N; i++)
            {
                summA *= -1;
                Summa(ref summA, ref summB, i - 1, i * (i + 1) );
            }
       }


        static int inputInt()
        {
            int x;
            string inputStr = Console.ReadLine();
            while (!Int32.TryParse(inputStr, out x))
            {
                Console.WriteLine("Некорректный ввод");
                inputStr = Console.ReadLine();
            }
            return x;

        }

        static void Summa(ref int a, ref int b, int c, int d)
        {
            a = a * d + b * c;
            b = b * d;
            Socr(ref a, ref b);
        }

        static void Socr(ref int a, ref int b)
        {
            int myNod = nod(a, b);
            if (myNod != 0)
            {
                a /= myNod;
                b /= myNod;
            }
        }

        static int nod(int a, int b)
        {
            a = Math.Abs(a);
            b = Math.Abs(b);

            if (a == 0 && b == 0)
            {
                return 1;
            }

            if (a == 0)
            {
                return b;
            }
            if (b == 0)
            {
                return a;
            }

            while (a != b)
            {
                if (a > b)
                    a -= b;
                else
                {
                    b -= a;
                }
            }
            return a;
        }

        static int Count(int x)
        {
            int delitel = 0;
            x = Math.Abs(x);
            if (x == 0) x = 1;
            while (x > 0)
            {
                x /= 10;
                delitel++;
            }
            return delitel;

        }

        static void Display(int a, int b)
        {
            Console.ForegroundColor = ConsoleColor.Magenta;
            Console.WriteLine("\n" + a);
            int count = 0;
            int countA = Count(a);
            int countB = Count(b);

            Console.ForegroundColor = ConsoleColor.White;

            if (a < 0)
            {
                countB--;
                Console.Write("-");
            }
            if (b < 0)
            {
                countA--;
                Console.Write("-");
            }

            if (countA > countB)
            {
                count = countA;
            }
            else
            {
                count = countB;
            }
            Console.ForegroundColor = ConsoleColor.White;
            while (count > 0)
            {
                Console.ForegroundColor = ConsoleColor.White;
                Console.Write("-");
                count--;
            }
            Console.ForegroundColor = ConsoleColor.Magenta;
            Console.WriteLine("\n" + b);

        }