class Program
{
    static void Main(string[] args)
    {
        FCalc fcalc = new FCalc();
        int n = 3;
        int x = 10;
        double result = 1;

        for (int i = 1; i <= n; i++)
        {
            result = Convert.ToDouble((x * i) / fcalc.Fact(n));
        }
        Console.WriteLine(result);
    }
}
   
    
class FCalc
{
     public int Fact(int n)
     {
         int resF = 1;
         for (int i = 1; i <= n; i++)
         {
             resF = resF * i;
         }
         return resF;
     }
}