import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    }

    static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    }

    static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) DiceandCoin solver = new DiceandCoin(); solver new DiceandCoin() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    } DiceandCoin public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        } solve {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        } int n = in.nextInt(); n in.nextInt() in.nextInt in int k = in.nextInt(); k in.nextInt() in.nextInt in double result = 0; result 0 for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            } {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            } int t = i; t i double tmp = 1; tmp 1 while (t < k) {
                    tmp /= 2;
                    t *= 2;
                } t < k t k {
                    tmp /= 2;
                    t *= 2;
                } tmp /= 2 tmp 2 t *= 2 t 2 result += tmp result tmp out.println(result / n) out.println out result / n result n int testNumber testNumber Scanner in in PrintWriter out out public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    }

    static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    }

    static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DiceandCoin solver = new DiceandCoin();
        solver.solve(1, in, out);
        out.close();
    }

    static class DiceandCoin {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();

            double result = 0;
            for (int i = 1; i <= n; i++) {
                int t = i;
                double tmp = 1;
                while (t < k) {
                    tmp /= 2;
                    t *= 2;
                }
                result += tmp;
            }
            out.println(result / n);

        }

    }
}

