import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	}
} Main public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int k = sc.nextInt(); k sc.nextInt() sc.nextInt sc sc.close() sc.close sc double ans = 0; ans 0 for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		} int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		} {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		} int s = i; s i double val = 1.0 / n; val 1.0 / n 1.0 n while (s < k) {
				s *= 2;
				val /= 2;
			} s < k s k {
				s *= 2;
				val /= 2;
			} s *= 2 s 2 val /= 2 val 2 ans += val ans val System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	}
} public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		sc.close();

		double ans = 0;
		for (int i = 1; i <= n; i++) {
			int s = i;
			double val = 1.0 / n;
			while (s < k) {
				s *= 2;
				val /= 2;
			}
			ans += val;
		}
		System.out.println(ans);
	}
}
