import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		// 整数の入力
		int n = sc.nextInt();
		int k = sc.nextInt();

		double ans = 0;
		double n2 = n;
		double value = 1;

		for(double i=n;i>0;){
			if(i*value<k){
				value *= 2;
			} else {
				ans += 1.0/(n*value);
				i--;
			}
		}

		// 出力
		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