import java.util.Scanner;

public class Main {
	static double N;
	static int K;
	static double ans;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		N = sc.nextInt();
		K = sc.nextInt();

		double prob = 1 / N;

		for (int point = 1; point <= N; point++) {
			dfs(point, 1/N);
		}

		System.out.println(ans);
	}

	private static void dfs(int point, double prob) {
		if (point >= K) {
			ans += prob;
			return;
		}

		dfs(point * 2, prob * 1/2);
	}

}
/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