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;
	      
	  double a = 1.0/n; 
	   for (int i=1; i<n+1; i++) {
		  int cn = i;
		   double t = a; 
		   while(cn<k) {
			     t = t*0.5;
			     cn= cn*2;
			    } 
		   
		   p = p+t ;
	   }
       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