import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final double N = sc.nextDouble();
        final double K = sc.nextDouble();

        double ans = 0;
        for (int i = 1; i <= N; i++) {
            double tmp = 1.0 / N;
            int now = i;
            while (now < K) {
                now *= 2;
                tmp /= 2;
            }
            ans += tmp;
        }

        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