
import java.util.*;
import java.math.*;
public class Main {
  
  	public static double halfpow (int a){
			double d = 0.5;
			return Math.pow(d,a);
		}
	
	public static void main(String[] args){
		
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		double ans = 0;


        for (int i = 1; i < N+1; i++) {
			int cnt = 0;
            int j = i; 
			while (j < K)
			{
				j*=2;
				cnt++;
			}
  
			ans += halfpow(cnt);
		}
		ans = ans / 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