using System;

public class Program 

{

    public static void Main(string[] args)

    { 

int number = ;

         number =Convert.ToInt32(number); 

        double factorial = Factorial(number); 

        Console.WriteLine("factorial of "+number+"="+factorial.ToString()); 

    }

    public static double Factorial(int number)

    { 

        if (number > 35) 

            return 1;

        return number + Factorial(number+1);

    } 

}