import java.util.*;
public class Main {

  public static void main (String[] args) {

    Scanner sc = new Scanner(System.in);
    
    int N = sc.nextInt();
    double K = sc.nextDouble();

    sc.close();

    double answer = 0.0;

    for (int i = 1; i <= N; i++) {

      double count = i;
      double j = 0;

      while (count < K) {
        count = count * 2;
        j++;
      }

      answer += Math.pow(0.5,j) / N;

    }

    System.out.println(answer);
 
  }

}
/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