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 p = 0;

		for(int i=1;i<=N;i++) {
			double pi = 1;
			int temp = i;
			while(temp < K) {
				pi /= 2;
				temp *= 2;
			}
			p += pi;
		}
		p /= N;
		System.out.println(p);
    }
}
/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