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();
        sc.close();

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    }

} 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();
        sc.close();

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    }

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

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = sc.nextInt();
        sc.close();

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    } 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 prob = 0.0; prob 0.0 for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        } {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        } int points = i; points i double diff = 1.0 / n; diff 1.0 / n 1.0 n while (points < k) {
                diff *= 0.5;
                points *= 2;
            } points < k points k {
                diff *= 0.5;
                points *= 2;
            } diff *= 0.5 diff 0.5 points *= 2 points 2 prob += diff prob diff System.out.println(prob) System.out.println System.out System System.out prob 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();
        sc.close();

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    }

} public class Main {

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

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    }

} 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();
        sc.close();

        // 確率
        double prob = 0.0;
        // サイコロが1からnの場合の各確率を求め、
        // それを合計したものが求めたい確率
        for (int i = 1; i <= n; i++) {
            int points = i;
            double diff = 1.0 / n;
            while (points < k) {
                diff *= 0.5;
                points *= 2;
            }
            prob += diff;
        }
        System.out.println(prob);
    }

}
