import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int k = sc.nextInt();
    double ans = 0;
    double count;
    for(int i = 1;i<=n;i++){//saikoro no me
      count = 0;
      int point = i;
      while(point<k){
        point*=2;
        count++;
      }
      point = 1;
      while(count!=17){
        count++;
        point*=2;
      }
      ans+=point;
    }
    ans/=(double)n;
    ans/=131072;
    System.out.println(ans);
  }
}

/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