// Page 251

import java.util.Scanner;
public class Prog_16_0Fraction
{
	public static double S (int n)
	{	if (n==1)
			return 0;
		else
			return (n-1.0)/n + S(n-1);
	}

	public static void main(String[] args)
	{
		double s = S(3);
		System.out.println("The result is: " + s);
	}
}