P6158 [CF2048G] Kevin and Matrices
NOI
题目描述

Kevin has been transported to Sacred Heart Hospital, which contains all the $n \times m$ matrices with integer values in the range $ [1,v] $.

Now, Kevin wants to befriend some matrices, but he is willing to befriend a matrix $ a $ if and only if the following condition is satisfied:

$$ \min_{1\le i\le n}\left(\max_{1\le j\le m}a_{i,j}\right)\le\max_{1\le j\le m}\left(\min_{1\le i\le n}a_{i,j}\right). $$

Please count how many matrices in Sacred Heart Hospital can be friends with Kevin.

Since Kevin is very friendly, there could be many matrices that meet this condition. Therefore, you only need to output the result modulo $998\,244\,353$.

Input

Each test contains multiple test cases. The first line contains the number of test cases $ t $ ($1 \le t \le 8\cdot 10^3$).

The only line of each test case contains three integers $n$, $m$, $v$ ($1 \le n, v, n \cdot v \leq 10^6$, $1 \le m \le 10^9$).

It is guaranteed that the sum of $n \cdot v$ over all test cases doesn't exceed $ 10^6 $.

Output

For each test case, output one integer — the number of matrices that can be friends with Kevin modulo $998\,244\,353$.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 2 2 2 2 3 4 11 45 14
样例输出
14 2824 883799966
提示

In the first test case, besides the matrices $a=\begin{bmatrix}1&2\\2&1\end{bmatrix}$ and $a=\begin{bmatrix}2&1\\1&2\end{bmatrix}$, which do not satisfy the condition, the remaining $2^{2 \cdot 2} - 2 = 14$ matrices can all be friends with Kevin.