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

namespace Cos
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Введите X:");
            double x = double.Parse(Console.ReadLine());
            double sum = 0.0;
            Console.Write("Введите N:");
            int N = int.Parse(Console.ReadLine());
            double Q = 1.0;
            for (int n = 1; n < N; n++)
            {
                sum += Q;
                Q*=   -x/ (2 * n);
                Console.Write("n={0}\t, Q={1}\t,Cумма={2}\t \n", n, Q, sum.ToString());
            }
            Console.WriteLine("Сумма={0}", sum.ToString());
            Console.WriteLine("Cos(-x)={0}\t", Math.Cos(-x));
            Console.ReadKey();
        }
    }
}