问题 B: Bloodline Counter

内存限制:512 MB 时间限制:2.000 S
评测方式:文本比较 命题人:
提交:1 解决:1

题目描述

A tournament is a directed graph obtained by assigning a direction for each edge in an undirected complete graph. We say a tournament is grand, if and only if the largest directed cycle in the tournament contains exactly k vertices. Please count the number of different labeled grand tournaments of n vertices modulo 998 244 353.

输入

The first line contains two integers n and k (3 ≤ k ≤ n ≤ 5×105 ), as explained in the problem statement.

输出

Output an integer representing the answer modulo 998 244 353.

样例输入 复制

3 3

样例输出 复制

2