import java.util.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        double n=sc.nextDouble();
        double k=sc.nextDouble();
  		double kaku=1/n;
  		double ans=0;
  		int d=0;
		
  		
		for(int c=1;c<=n;c++){
          	d=c;
    		while(d<k){
             kaku*=0.5;
             d*=2;
            }
          ans+=kaku;
          
          kaku=1/n;
    	}
    
    	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