atcoder#ABC275E. [ABC275E] Sugoroku 4

[ABC275E] Sugoroku 4

Score : 500500 points

Problem Statement

Takahashi is playing sugoroku, a board game.

The board has N+1N+1 squares, numbered 00 to NN. Takahashi starts at square 00 and goes for square NN.

The game uses a roulette wheel with MM numbers from 11 to MM 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 NN, he turns around at square NN and goes back by the excessive number of squares.

For instance, assume that N=4N=4 and Takahashi is at square 33. If the wheel shows 44, the excessive number of squares beyond square 44 is 3+44=33+4-4=3. Thus, he goes back by three squares from square 44 and arrives at square 11.

When Takahashi arrives at square NN, he wins and the game ends.

Find the probability, modulo 998244353998244353, that Takahashi wins when he may spin the wheel at most KK 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 yx\frac{y}{x}, it is guaranteed that xx is not divisible by 998244353998244353.

Here, there is a unique integer zz between 00 and 998244352998244352 such that xzy(mod998244353)xz \equiv y \pmod{998244353}. Print this zz.

Constraints

  • MN1000M \leq N \leq 1000
  • 1M101 \leq M \leq 10
  • 1K10001 \leq K \leq 1000
  • All values in the input are integers.

Input

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

NN MM KK

Output

Print the answer.

2 2 1
499122177

Takahashi wins in one spin if the wheel shows 22. Therefore, the probability of winning is 12\frac{1}{2}.

We have 2×4991221771(mod998244353)2\times 499122177 \equiv 1 \pmod{998244353}, so the answer to be printed is 499122177499122177.

10 5 6
184124175
100 1 99
0