import java.util.*;
import java.util.stream.*;

public class Main {
  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    int N = in.nextInt();
    int K = in.nextInt();
    double sum = 0;
    for (int i = 1; i <= N; i++) {
      if (K <= i) {
        sum++;
        continue;
      }
      int value = i, p = 1;
      while (value < (K + 1) / 2) {
        value *= 2;
        p++;
      }
      sum += Math.pow(0.5, p);
    }
    System.out.println(sum / N);
  }
}
/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