import java.util.Scanner;
public class Main{
	public static void main(String[]args){
		double ans=0.000000000;
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int k=sc.nextInt();
		 for(int i=1;i<=n;i++){
			    long temp=i;
			    long tri=0;
			    while(temp<k){
			      temp*=2;
			      tri++;
			    }
			    ans+=1.000000000/(n*Math.pow(2,tri));
			 }
		 System.out.println(ans);
	}
}

/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