题目描述
Problem Statement
Find the number of ways, modulo 998244353, to fill the squares of an $N \times N$ grid using each integer from 1 to N^2 once so that every square satisfies at least one of the following conditions.
- In the same column, there is a square containing a number greater than that of the concerned square.
- In the same row, there is a square containing a number less than that of the concerned square.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer.
Constraints
- $1 \leq N \leq 500$
Sample Input 1
2
Sample Output 1
8
Here is one way to fill the grid to satisfy the requirement.
13
42
Here, the top-left square contains a number less than that of the bottom-left square, satisfying the first condition. It does not satisfy the second condition, however.
Sample Input 2
5
Sample Output 2
704332752
Sample Input 3
100
Sample Output 3
927703658
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
2
样例输出
8