import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = sc.nextInt();
        double ret = 0;
        for (int i = 1; i <= n; i++) {
            double tmp = 1.0 / n;
            int now = i;
            while (now < k) {
                now *= 2;
                tmp /= 2;
            }
            ret += tmp;
        }
        System.out.println(ret);
        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