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 pp = 0;

    for(int i=1; i<=n; i++){
      int count = 0;
      int m = i;
      while(m<k){
        m = m * 2;
        count +=1;
      }
      pp += 1/Math.pow(2, count);
    }

    System.out.println(pp*1/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