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 result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	}
} import java.util.Scanner; Scanner 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 result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		double result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	} main {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		double result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	} 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 double result = 0; result 0 for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		} int i = 1; int i = 1; i 1 i <= N i N i++ i++ i {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		} {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		} double a = 1d / N; a 1d / N 1d N int total = i; total i while(total < K) {
				total *= 2;
				a = a * 0.5;
			} total < K total K {
				total *= 2;
				a = a * 0.5;
			} total *= 2 total 2 a = a * 0.5 a a * 0.5 a 0.5 result += a result a System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		double result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		double result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	}
} Main
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 result = 0;
		for(int i = 1; i <= N; i++) {
			double a = 1d / N;
			int total = i;
			while(total < K) {
				total *= 2;
				a = a * 0.5;
			}
			result += a;
		}
		System.out.println(result);
	}
}
