import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    double n = sc.nextDouble();
    double k = sc.nextDouble();
    double answer = 0;
    for(double i=1;i<=n;i++){
      double coinCnt =0;
      coinCnt=Math.ceil((Math.log(k)/Math.log(2))-(Math.log(i)/Math.log(2)));
      if(coinCnt<=0){
        coinCnt=0;
      }
      answer += 1/Math.pow(2,coinCnt);
    }
    System.out.println(answer*(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