import java.util.Scanner;

public class Main
{

	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);

		double n = Integer.parseInt(sc.next());
		double k = Integer.parseInt(sc.next());

		double sum = 0;

		for (int i = 1; i <= n; i++) {
			if (i >= k) {
				sum += 1.0;
			} else {
				sum += Math.pow(0.5, Math.ceil(log2(k/i)));
			}
		}

		System.out.println(sum / n);

		sc.close();
	}

	public static double log2(double d)
	{
		return Math.log(d) / Math.log(2);
	}
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz