题目描述
Problem Statement
Snuke loves permutations. He is making a permutation of length N.
Since he hates the integer K, his permutation will satisfy the following:
- Let the permutation be a_1, a_2, ..., a_N. For each $i = 1,2,...,N, |a_i - i| \neq K$.
Among the N! permutations of length N, how many satisfies this condition?
Since the answer may be extremely large, find the answer modulo 924844033(prime).
Input
The input is given from Standard Input in the following format:
N K
Output
Print the answer modulo 924844033.
Constraints
- 2 ≦ N ≦ 2000
- 1 ≦ K ≦ N-1
Sample Input 1
3 1
Sample Output 1
2
2 permutations (1, 2, 3), (3, 2, 1) satisfy the condition.
Sample Input 2
4 1
Sample 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.
Sample Input 3
4 2
Sample Output 3
9
Sample Input 4
4 3
Sample Output 4
14
Sample Input 5
425 48
Sample Output 5
756765083
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分