# PERMUT1 - Permutations

## 题目描述

Let A = \[a \$ _{1} \$ ,a \$ _{2} \$ ,...,a \$ _{n} \$ \] be a permutation of integers 1,2,...,n. A pair of indices (i,j), 1<=i<=j<=n, is an _inversion_ of the permutation A if a \$ _{i} \$ >a \$ _{j} \$ . We are given integers n>0 and k>=0. What is the number of n-element permutations containing exactly k inversions? For instance, the number of 4-element permutations with exactly 1 inversion equals 3. ### Task Write a program which for each data set from a sequence of several data sets: - reads integers n and k from input, - computes the number of n-element permutations with exactly k inversions, - writes the result to output.

## 输入输出格式

### 输入格式

The first line of the input file contains one integer d, 1<=d<=10, which is the number of data sets. The data sets follow. Each data set occupies one line of the input file and contains two integers n (1<=n<=12) and k (0<=k<=98) separated by a single space.

### 输出格式

The i-th line of the output file should contain one integer - the number of n-element permutations with exactly k inversions.

## 输入输出样例

### 输入样例 #1

``````1
4 1``````

### 输出样例 #1

``3``