import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double n = scan.nextInt();
        double k = scan.nextInt();
        int a = 0;
        int c = 0;
        double out = 0;
        for(int i = 1; i <= n; i++){
            a = i;
            while(a < k){
                a *= 2;
                c++;
            }
            out += (1 / n) * Math.pow(0.5, c);
            c = 0;
        }
        System.out.println(out);
    }
}

/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