import java.util.*;

public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        Double sco = 0.0;
        for (int i = 1; i <= a; i++) {
            int co = 0;
            for (int j = i; j < b;j *= 2 ) {
                co += 1;

            }

            sco += (1.0 / a) * Math.pow(0.5, co);
        }
        System.out.println(sco);
    }
}

/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