题目描述
Problem Statement
How many integer sequences $A=(A_1,\ldots,A_N)$ of length N satisfy all the conditions below?
-
$1\le A_i \le M (1 \le i \le N)$
-
|A_i - A_{i+1}| \geq K (1 \le i \le N - 1)
Since the count can be enormous, find it modulo 998244353.
Input
Input is given from Standard Input in the following format:
N M K
Output
Print the count modulo 998244353.
Constraints
- $2 \leq N \leq 1000$
- $1 \leq M \leq 5000$
- $0 \leq K \leq M-1$
- All values in input are integers.
Sample Input 1
2 3 1
Sample Output 1
6
The following 6 sequences satisfy the conditions.
- (1,2)
- (1,3)
- (2,1)
- (2,3)
- (3,1)
- (3,2)
Sample Input 2
3 3 2
Sample Output 2
2
The following 2 sequences satisfy the conditions.
- (1,3,1)
- (3,1,3)
Sample Input 3
100 1000 500
Sample Output 3
657064711
Print the count modulo 998244353.
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 3 1
样例输出
6