//A116г

import java.util.*;
import java.lang.*;
import java.io.*;

class ThirdLab
{
	public static void main (String[] args)
	{
		Scanner input = new Scanner(System.in);
		double x, mult = 1;
		int n, k, fact = 1;
		
		n = input.nextInt();
		x = input.nextDouble();
		
		for(k = 1; k <= n; k++)
		{
			fact *= k;
			mult *= 1 + (Math.sin(k*x)/fact);
		}
		
		System.out.printf("%.4f", mult);
	}
}