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

namespace Factorial
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Введите число: ");
            int number = int.Parse(Console.ReadLine());
            Factorial(number);
            string output = String.Format("Факториал вашего числа равен {0}", Factorial(number));
            Console.WriteLine(output);
            Console.ReadLine();
        }

        public static double Factorial(double i)
        {

            if (i == 0)
            {
                return 1;
            }
            else
            {
                double returnNumber = i * Factorial(i - 1);
                return returnNumber;
            }
        }
    }
}