using System;

public class Program

{

    public static double P(double n, long x)

    {

        if (n == 0) return 1;

        if (n == 1) return x;

        else return ((2*n-1)*x*P(n-1, x)-(n-1)*P(n-2, x))/n;

    }

    public static void Main (string[] args)

    {

        Console.Write("Enter x: ");

        int x = int.Parse (Console.ReadLine());

        Console.Write("Enter n: ");

        int n = int.Parse (Console.ReadLine());

        Console.WriteLine(P(n, x));

    }

}

​