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();
        double Ans= 0.0;
        for(double i=1.0; i<=N;i++){Ans += 1/((i < K) ? Math.pow(2,Math.ceil(Math.log(K/i)/Math.log(2.0))) : 1.0);}
        Ans /= N;
        System.out.println(Ans);
        sc.close();
    }
}
/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