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 n0 = (double) 1/n;
      double count = 0;
      int point = 0;
      double per = 0;
      for(int i = 1;i <= n;i++){
        point = i;
      	while(point < k){
        	count++;
            point = point*2;
        }
        per += n0*Math.pow(0.5,count);
        count = 0;
      }
      System.out.println(per);
    }
}
/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