P24405 [AtCoder] Sugoroku 4
普及+
题目描述

Problem Statement

Takahashi is playing sugoroku, a board game.
The board has N+1 squares, numbered 0 to N.
Takahashi starts at square 0 and goes for square N.
The game uses a roulette wheel with M numbers from 1 to M that appear with equal probability.
Takahashi spins the wheel and moves by the number of squares indicated by the wheel. If this would send him beyond square N, he turns around at square N and goes back by the excessive number of squares.
For instance, assume that N=4 and Takahashi is at square 3. If the wheel shows 4, the excessive number of squares beyond square 4 is 3+4-4=3. Thus, he goes back by three squares from square 4 and arrives at square 1.
When Takahashi arrives at square N, he wins and the game ends.
Find the probability, modulo 998244353, that Takahashi wins when he may spin the wheel at most K times.

How to print a probability modulo 998244353
It can be proved that the sought probability is always a rational number.
Additionally, under the Constraints of this problem, when the sought probability is represented as an irreducible fraction $\frac{y}{x}$, it is guaranteed that x is not divisible by 998244353.
Here, there is a unique integer z between 0 and 998244352 such that xz $\equiv y \pmod{998244353}$. Print this z.

Input

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

Output

Print the answer.

Constraints

  • $M \leq N \leq 1000$
  • $1 \leq M \leq 10$
  • $1 \leq K \leq 1000$
  • All values in the input are integers.

Sample Input 1

2 2 1

Sample Output 1

499122177

Takahashi wins in one spin if the wheel shows 2. Therefore, the probability of winning is $\frac{1}{2}$.
We have $2\times 499122177 \equiv 1 \pmod{998244353}$, so the answer to be printed is 499122177.

Sample Input 2

10 5 6

Sample Output 2

184124175

Sample Input 3

100 1 99

Sample Output 3

0

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 2 1
样例输出
499122177