import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		double p = 0;

		for (int i = 1; i < N + 1; i++) {
			int cnt = 0;
			int pt = i;
			while (pt <= K - 1) {
				pt *= 2;
				cnt++;
			}

			p += (double) 1 / N * Math.pow(0.5, cnt);
		}

		System.out.println(p);

	}
}

/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