#exawizards2019e. [exawizards2019_e]Black or White

[exawizards2019_e]Black or White

Problem Statement

Today, Snuke will eat BB pieces of black chocolate and WW 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 ii from 11 to B+WB+W (inclusive), find the probability that the color of the ii-th piece to be eaten is black. It can be shown that these probabilities are rational, and we ask you to print them modulo 109+710^9 + 7, as described in Notes.

Notes

When you print a rational number, first write it as a fraction fracyx\\frac{y}{x}, where x,yx, y are integers and xx is not divisible by 109+710^9 + 7 (under the constraints of the problem, such representation is always possible). Then, you need to print the only integer zz between 00 and 109+610^9 + 6, inclusive, that satisfies xzequivypmod109+7xz \\equiv y \\pmod{10^9 + 7}.

Constraints

  • All values in input are integers.
  • 1leqB,Wleq1051 \\leq B,W \\leq 10^{5}

Input

Input is given from Standard Input in the following format:

BB WW

Output

Print the answers in B+WB+W lines. In the ii-th line, print the probability that the color of the ii-th piece to be eaten is black, modulo 109+710^{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 frac12,frac14,frac14\\frac{1}{2}, \\frac{1}{4}, \\frac{1}{4}, respectively. Thus, the probabilities of eating a black piece first, second and third are frac12,frac34\\frac{1}{2},\\frac{3}{4} and frac34\\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 frac1116\\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