Problem:
Score : 700 points

Problem Statement

Today, Snuke will eat B pieces of black chocolate and W pieces of white chocolate for an afternoon snack.

He will repeat the following procedure until there is no piece left:

Choose black or white with equal probability, and eat a piece of that color if it exists.

For each integer i from 1 to B+W (inclusive), find the probability that the color of the i-th piece to be eaten is black.
It can be shown that these probabilities are rational, and we ask you to print them modulo 10^9 + 7, as described in Notes.

Notes

When you print a rational number, first write it as a fraction \frac{y}{x}, where x, y are integers and x is not divisible by 10^9 + 7
(under the constraints of the problem, such representation is always possible).
Then, you need to print the only integer z between 0 and 10^9 + 6, inclusive, that satisfies xz \equiv y \pmod{10^9 + 7}.

Constraints

All values in input are integers.

1 \leq B,W \leq 10^{5}

Input

Input is given from Standard Input in the following format:

B W

Output

Print the answers in B+W lines. In the i-th line, print the probability that the color of the i-th piece to be eaten is black, modulo 10^{9}+7.

Sample Input 1

2 1

Sample Output 1

500000004
750000006
750000006

There are three possible orders in which Snuke eats the pieces:

white, black, black

black, white, black

black, black, white

with probabilities \frac{1}{2}, \frac{1}{4}, \frac{1}{4}, respectively. Thus, the probabilities of eating a black piece first, second and third are \frac{1}{2},\frac{3}{4} and \frac{3}{4}, respectively.

Sample Input 2

3 2

Sample Output 2

500000004
500000004
625000005
187500002
187500002

They are \frac{1}{2},\frac{1}{2},\frac{5}{8},\frac{11}{16} and \frac{11}{16}, respectively.

Sample Input 3

6 9

Sample Output 3

500000004
500000004
500000004
500000004
500000004
500000004
929687507
218750002
224609377
303710940
633300786
694091802
172485353
411682132
411682132

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;

using E = System.Linq.Enumerable;

internal partial class Solver {
    Binomial _B;
    public void Run() {
        var B = ni();
        var W = ni();
        var mod = 1000000000 + 7;
        ModInt.SetModValue(mod);
        _B = new Binomial(W + B + 1, mod);
        cout.WriteLine(string.Join("\n", Solve(B, W)));
    }

    private int[] Solve(int b, int w) {
        var n = b + w;
        var ans = new ModInt[n + 1];
        var two = new ModInt[n + 1];
        two[0] = 1;
        var allpattern = _B[b + w, b];
        for (int i = 1; i < two.Length; i++) {
            two[i] = two[i - 1] * 2;
        }
        for (int i = 1; i <= w; i++) { // ***BWWW...WWW
            var remB = b - 1;
            var remW = w - i;
            ModInt pattern = _B[remB + remW, remB];
            pattern /= two[remB + remW + 1];
            if (remB + remW > 0) {
                var bothpattern = pattern * remB / (remB + remW);
                ans[0] += bothpattern;
                ans[remB + remW] -= bothpattern;
            }
            ans[remB + remW] += pattern;
            ans[remB + remW + 1] -= pattern;
        }
        for (int i = 1; i <= b; i++) { // ***WBBB...BBB
            var remB = b - i;
            var remW = w - 1;
            ModInt pattern = _B[remB + remW, remB];
            pattern /= two[remB + remW + 1];
            if (remB + remW > 0) {
                var bothpattern = pattern * remB / (remB + remW);
                ans[0] += bothpattern;
                ans[remB + remW] -= bothpattern;
            }
            ans[remB + remW + 1] += pattern;
        }
        for (int i = 1; i < ans.Length; i++) {
            ans[i] += ans[i - 1];
        }
        return ans.Select(a => (a).ToInt()).Take(n).ToArray();
    }
}


public class Binomial {
    private readonly long[] factorial;
    private readonly long[] inverseFactorial;
    private readonly long[] inverse;
    private readonly int mod;

    public Binomial(int size, int primeMod) {
        size++;
        factorial = new long[size];
        inverseFactorial = new long[size];
        inverse = new long[size];
        mod = primeMod;
        Setup(size);
    }

    private void Setup(int size) {
        factorial[0] = factorial[1] = 1;
        inverseFactorial[0] = inverseFactorial[1] = 1;
        inverse[1] = 1;
        for (int i = 2; i < size; i++) {
            factorial[i] = factorial[i - 1] * i % mod;
            inverse[i] = (mod - (mod / i) * inverse[mod % i] % mod);
            inverseFactorial[i] = inverseFactorial[i - 1] * inverse[i] % mod;
        }
    }

    private long C(int s, int t) {
        if (s < 0 || t < 0 || s < t) {
            return 0;
        }

        if (t == 0 || s == t) {
            return 1;
        }

        if (s >= mod) {
            return C(s % mod, t % mod) * C(s / mod, t / mod) % mod; // Lucas' theorem
        }

        return factorial[s] * inverseFactorial[t] % mod * inverseFactorial[s - t] % mod;
    }

    public long this[int s, int t] {
        get {
            return C(s, t);
        }
    }

    public long P(int s, int t) {
        if (s < 0 || t < 0 || s < t) return 0;
        return factorial[s] * inverseFactorial[s - t] % mod;
    }

    public long H(int s, int t) {
        if (s < 0 || t < 0) return 0;
        if (s == 0 && t == 0) return 1;
        return C(s + t - 1, s);
    }

    public long H1(int s, int t) {
        return H(s - t, t);
    }
}
public struct ModInt {
    private static int mod = 0;
    private long value;

    public ModInt(long x) {
        value = x;
        Normalize();
    }

    private static long RegularMod(long x, int mod) {
        if (x >= mod) {
            if (x < 2 * mod) {
                return x - mod;
            }

            return x % mod;
        }
        if (x >= 0) {
            return x;
        }

        x = mod - RegularMod(-x, mod);
        if (x == mod) {
            return 0;
        }

        return x;
    }

    public static void SetModValue(int m) {
        ModInt.mod = m;
    }

    private void Normalize() {
        value = RegularMod(value, mod);
    }

    public override string ToString() {
        return value.ToString();
    }

    public int ToInt() {
        return (int)value;
    }

    public static bool operator ==(ModInt c1, ModInt c2) {
        return c1.value == c2.value;
    }

    public static bool operator !=(ModInt c1, ModInt c2) {
        return !(c1 == c2);
    }

    public static ModInt operator +(ModInt x, ModInt y) {
        return new ModInt(x.value + y.value);
    }
    public static ModInt operator -(ModInt x, ModInt y) {
        return new ModInt(x.value - y.value);
    }
    public static ModInt operator *(ModInt x, ModInt y) {
        return new ModInt(x.value * y.value);
    }
    public static ModInt operator /(ModInt x, ModInt y) {
        return new ModInt(x.value * Inverse(y.value, mod));
    }

    private static long ExtendedGcd(long a, long b, ref long x, ref long y) {
        if (b == 0) {
            x = 1; y = 0;
            return a;
        } else {
            long d = ExtendedGcd(b, a % b, ref y, ref x);
            y -= a / b * x;
            return d;
        }
    }

    private static long Inverse(long a, long mod) {
        long x = 0, y = 0;
        if (ExtendedGcd(a, mod, ref x, ref y) == 1) {
            return (x + mod) % mod;
        } else {
            throw new Exception("Invalid inverse " + a + " " + mod);
        }
    }

    public static implicit operator ModInt(long x) {
        return new ModInt(x);
    }

    public override bool Equals(object obj) {
        if (obj == null) {
            return false;
        }
        return value.Equals(((ModInt)obj).value);
    }

    public override int GetHashCode() {
        return value.GetHashCode();
    }
}

// PREWRITEN CODE BEGINS FROM HERE
internal partial class Solver : Scanner {
    public static void Main(string[] args) {
#if LOCAL
        byte[] inputBuffer = new byte[1000000];
        var inputStream = Console.OpenStandardInput(inputBuffer.Length);
        Console.SetIn(new StreamReader(inputStream, Console.InputEncoding, false, inputBuffer.Length));
        new Solver(Console.In, Console.Out).Run();
#else
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver(Console.In, Console.Out).Run();
        Console.Out.Flush();
#endif
    }

#pragma warning disable IDE0052
    private readonly TextReader cin;
    private readonly TextWriter cout;
#pragma warning restore IDE0052

    public Solver(TextReader reader, TextWriter writer)
        : base(reader) {
        cin = reader;
        cout = writer;
    }
    public Solver(string input, TextWriter writer)
        : this(new StringReader(input), writer) {
    }

#pragma warning disable IDE1006
#pragma warning disable IDE0051
    private int ni() { return NextInt(); }
    private int[] ni(int n) { return NextIntArray(n); }
    private long nl() { return NextLong(); }
    private long[] nl(int n) { return NextLongArray(n); }
    private double nd() { return NextDouble(); }
    private double[] nd(int n) { return NextDoubleArray(n); }
    private string ns() { return Next(); }
    private string[] ns(int n) { return NextArray(n); }
#pragma warning restore IDE1006
#pragma warning restore IDE0051
}

internal static class LinqPadExtension {
    public static T Dump<T>(this T obj) {
#if LOCAL
        return LINQPad.Extensions.Dump(obj);
#else
        return obj;
#endif
    }
}

public class Scanner {
    private readonly TextReader Reader;
    private readonly Queue<string> TokenQueue = new Queue<string>();
    private readonly CultureInfo ci = CultureInfo.InvariantCulture;

    public Scanner()
        : this(Console.In) {
    }

    public Scanner(TextReader reader) {
        Reader = reader;
    }

    public int NextInt() { return int.Parse(Next(), ci); }
    public long NextLong() { return long.Parse(Next(), ci); }
    public double NextDouble() { return double.Parse(Next(), ci); }
    public string[] NextArray(int size) {
        string[] array = new string[size];
        for (int i = 0; i < size; i++) {
            array[i] = Next();
        }

        return array;
    }
    public int[] NextIntArray(int size) {
        int[] array = new int[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextInt();
        }

        return array;
    }

    public long[] NextLongArray(int size) {
        long[] array = new long[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextLong();
        }

        return array;
    }

    public double[] NextDoubleArray(int size) {
        double[] array = new double[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextDouble();
        }

        return array;
    }

    public string Next() {
        if (TokenQueue.Count == 0) {
            if (!StockTokens()) {
                throw new InvalidOperationException();
            }
        }
        return TokenQueue.Dequeue();
    }

    public bool HasNext() {
        if (TokenQueue.Count > 0) {
            return true;
        }

        return StockTokens();
    }

    private static readonly char[] _separator = new[] { ' ', '\t' };
    private bool StockTokens() {
        while (true) {
            string line = Reader.ReadLine();
            if (line == null) {
                return false;
            }

            string[] tokens = line.Split(_separator, StringSplitOptions.RemoveEmptyEntries);
            if (tokens.Length == 0) {
                continue;
            }

            foreach (string token in tokens) {
                TokenQueue.Enqueue(token);
            }

            return true;
        }
    }
}