import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        int k = Integer.parseInt(sc.next());
        sc.close();
        double sum = 0;
        for (int i = 1; i <= n; i++) {
            if (i >= k) {
                sum += 1;
                continue;
            }
            int cnt = 1;
            while (k > i * Math.pow(2, cnt)) {
                cnt++;
            }
            sum += Math.pow(0.5, cnt);
        }
        sum /= n;
        System.out.println(sum);
    }
}
/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