import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.StringTokenizer;
public class Main {
	public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	}

}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
     }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.InputStreamReader; InputStreamReader java.io import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.StringTokenizer; StringTokenizer java.util public class Main {
	public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	}

} Main public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	} main {
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	} FastScanner sc = new FastScanner(System.in); sc new FastScanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int K = sc.nextInt(); K sc.nextInt() sc.nextInt sc long A = 0; A 0 long B = 0; B 0 BigDecimal n = new BigDecimal(N); n new BigDecimal(N) BigDecimal p = new BigDecimal("0"); p new BigDecimal("0") for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		} int i=1; int i=1; i 1 i<=N i N i++ i++ i {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		} {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		} int score = i; score i int num = 0; num 0 while(score < K) {
				score *= 2;
				num++;
			} score < K score K {
				score *= 2;
				num++;
			} score *= 2 score 2 num++ num if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			} i == 1 i 1 {
				A = (long) (Math.pow(2, num) * N);
			} A = (long) (Math.pow(2, num) * N) A (long) (Math.pow(2, num) * N) Math.pow(2, num) Math.pow Math 2 num N B += A / (long) (Math.pow(2, num) * N) B A / (long) (Math.pow(2, num) * N) A (long) (Math.pow(2, num) * N) Math.pow(2, num) Math.pow Math 2 num N p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP) p new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP) new BigDecimal(B).divide new BigDecimal(B) new BigDecimal(A) 15 RoundingMode.HALF_UP RoundingMode RoundingMode.HALF_UP System.out.println(p) System.out.println System.out System System.out p String[] args args class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
     }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
} FastScanner private BufferedReader reader = null; reader null private StringTokenizer tokenizer = null; tokenizer null public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    } FastScanner {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    } reader = new BufferedReader(new InputStreamReader(in)) reader new BufferedReader(new InputStreamReader(in)) tokenizer = null tokenizer null InputStream in in public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    } next {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            } catch (IOException e) {
                throw new RuntimeException(e);
            } IOException e {
                throw new RuntimeException(e);
            } throw new RuntimeException(e); new RuntimeException(e) {
                tokenizer = new StringTokenizer(reader.readLine());
            } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    } nextLine {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            } catch (IOException e) {
                throw new RuntimeException(e);
            } IOException e {
                throw new RuntimeException(e);
            } throw new RuntimeException(e); new RuntimeException(e) {
                return reader.readLine();
            } return reader.readLine(); reader.readLine() reader.readLine reader return tokenizer.nextToken("\n"); tokenizer.nextToken("\n") tokenizer.nextToken tokenizer "\n" public long nextLong() {
        return Long.parseLong(next());
    } nextLong {
        return Long.parseLong(next());
    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public int nextInt() {
        return Integer.parseInt(next());
    } nextInt {
        return Integer.parseInt(next());
    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public double nextDouble() {
         return Double.parseDouble(next());
     } nextDouble {
         return Double.parseDouble(next());
     } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    } nextIntArray {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    } int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++)
            a[i] = nextInt(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextInt(); a[i] = nextInt() a[i] a i nextInt() nextInt return a; a int n n public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } nextLongArray {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } long[] a = new long[n]; a new long[n] n for (int i = 0; i < n; i++)
            a[i] = nextLong(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextLong(); a[i] = nextLong() a[i] a i nextLong() nextLong return a; a int n n public class Main {
	public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	}

} public class Main {
	public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	}

} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.StringTokenizer;
public class Main {
	public static void main(String[] args){
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();
		long A = 0;
		long B = 0;

		BigDecimal n = new BigDecimal(N);
		BigDecimal p = new BigDecimal("0");

		for (int i=1;i<=N;i++) {
			int score = i;
			int num = 0;
			while(score < K) {
				score *= 2;
				num++;
			}
			if (i == 1) {
				A = (long) (Math.pow(2, num) * N);
			}
			B += A / (long) (Math.pow(2, num) * N);



//			p = p.add(new BigDecimal(1).divide( new BigDecimal(Math.pow(2, num)) ).divide(n, RoundingMode.HALF_EVEN));
		}
		p = new BigDecimal(B).divide(new BigDecimal(A),15, RoundingMode.HALF_UP);
		System.out.println(p);
	}

}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
     }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
}