Score : $600$ points
There is a grid with $H$ horizontal rows and $W$ vertical columns, where each square contains a digit between $1$ and $9$. For each pair of integers $(i, j)$ such that $1 \leq i \leq H$ and $1 \leq j \leq W$, the digit written on the square at the $i$-th row from the top and $j$-th column from the left is $c_{i, j}$.
Using this grid, Takahashi and Aoki will play together. First, Takahashi chooses a square and puts a piece on it. Then, the two will repeat the following procedures, 1. through 4., $N$ times.
After that, there will be $2N$ digits written on the blackboard. Let $d_1, d_2, \ldots, d_{2N}$ be those digits, in the order they are written. The two boys will concatenate the $2N$ digits in this order to make a $2N$-digit integer $X := d_1d_2\ldots d_{2N}$.
Find the number, modulo $998244353$, of different integers that $X$ can become.
Input is given from Standard Input in the following format:
$H$ $W$ $N$ $c_{1, 1}$$c_{1, 2}$$\cdots$$c_{1, W}$ $c_{2, 1}$$c_{2, 2}$$\cdots$$c_{2, W}$ $\vdots$ $c_{H, 1}$$c_{H, 2}$$\cdots$$c_{H, W}$
Print the number, modulo $998244353$, of different integers that $X$ can become.
2 2 1 31 41
5
Below is one possible scenario.
In this case, we have $X = 34$.
Below is another possible scenario.
In this case, we have $X = 11$.
Other than these, $X$ can also become $33$, $44$, or $43$, but nothing else.
That is, there are five integers that $X$ can become, so we print $5$.
2 3 4 777 777
1
$X$ can only become $77777777$.
10 10 300 3181534389 4347471911 4997373645 5984584273 1917179465 3644463294 1234548423 6826453721 5892467783 1211598363
685516949
Be sure to find the count modulo $998244353$.