
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double n = sc.nextDouble();
		double k = sc.nextDouble();
		sc.close();
		
		double p = 0;
		
		for(int i=1; i<=n; i++) {
			if(i<k) {
				p += 1/n * Math.pow(0.5, (int)(Math.log10((k-1)/i)/Math.log10(2)+1));
			}else {
				p += 1/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