AtCoder Grand Contest 005
D
~K Perm Counting
AtCoder
⌀ 2943
原题
← CE →
翻译中…

Problem Statement

翻译中…

Snuke loves permutations. He is making a permutation of length $N$.

翻译中…

Since he hates the integer $K$, his permutation will satisfy the following:

翻译中…
  • Let the permutation be $a_1, a_2, ..., a_N$. For each $i = 1,2,...,N$, $|a_i - i| \neq K$.
翻译中…

Among the $N!$ permutations of length $N$, how many satisfies this condition?

翻译中…

Since the answer may be extremely large, find the answer modulo $924844033$(prime).

翻译中…

Constraints

翻译中…
  • $2 ≦ N ≦ 2000$
  • $1 ≦ K ≦ N-1$
翻译中…

Input

翻译中…

The input is given from Standard Input in the following format:

翻译中…

N K

翻译中…

Output

翻译中…

Print the answer modulo $924844033$.

翻译中…

样例

Input #1
3 1
Output #1
2
$2$ permutations $(1, 2, 3)$, $(3, 2, 1)$ satisfy the condition.
Input #2
4 1
Output #2
5
$5$ permutations $(1, 2, 3, 4)$, $(1, 4, 3, 2)$, $(3, 2, 1, 4)$, $(3, 4, 1, 2)$, $(4, 2, 3, 1)$ satisfy the condition.
Input #3
4 2
Output #3
9
Input #4
4 3
Output #4
14
Input #5
425 48
Output #5
756765083
题目信息
题号
agc005_d
时间限制
2 s
内存限制
256 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。