import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		int k = sc.nextInt();

		double exp = (double) 1 / n;
		double sum = 0;

		for (int i = 1; i <= n; i++) {
			int count = 1;
			int tmp = i;
			while (tmp < k) {
				tmp *= 2;
				count *= 2;
			}
			sum += exp / count;
		}

		System.out.println(sum);

	}
}
/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