409416: GYM103535 D Link with Balls
Description
There were a lot of balls in the factory of Ball Illusion Technology(BIT). Link, a boy, went there to get some balls, but suddenly, he found that there were too many ways to get balls.
There are $$$2n$$$ buckets in the factory. Link may get $$$kx$$$ balls from the $$$2x-1^{th}$$$ bucket, where $$$k$$$ is a non-negtive integer. He may also get at most $$$x$$$ balls from the $$$2x^{th}$$$ bucket.
Link wanted to get $$$m$$$ balls, and he wondered how many ways there were to take out exactly $$$m$$$ balls. While Link is calculating the answer, he wants you to calculate it as well, and you should output the answer modulo $$$10^9+7$$$.
InputThe input consists of multiple test cases.
The first line contains an integer $$$T$$$ ($$$1 \leq T \leq 10^5$$$) – the number of test cases.
Each test case contains two integers $$$n$$$ and $$$m$$$($$$1 \leq n,m \leq 10^6$$$).
OutputFor each test case, print the answer modulo $$$10^9+7$$$ in a single line.
ExampleInput4 1 1 2 2 3 3 1000000 1000000Output
2 6 20 192151600