Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

The problem statement has recently been changed. View the changes.

×
E. Colorings and Dominoes

time limit per test

3 secondsmemory limit per test

512 megabytesinput

standard inputoutput

standard outputYou have a large rectangular board which is divided into $$$n \times m$$$ cells (the board has $$$n$$$ rows and $$$m$$$ columns). Each cell is either white or black.

You paint each white cell either red or blue. Obviously, the number of different ways to paint them is $$$2^w$$$, where $$$w$$$ is the number of white cells.

After painting the white cells of the board, you want to place the maximum number of dominoes on it, according to the following rules:

- each domino covers two adjacent cells;
- each cell is covered by at most one domino;
- if a domino is placed horizontally (it covers two adjacent cells in one of the rows), it should cover only red cells;
- if a domino is placed vertically (it covers two adjacent cells in one of the columns), it should cover only blue cells.

Let the value of the board be the maximum number of dominoes you can place. Calculate the sum of values of the board over all $$$2^w$$$ possible ways to paint it. Since it can be huge, print it modulo $$$998\,244\,353$$$.

Input

The first line contains two integers $$$n$$$ and $$$m$$$ ($$$1 \le n, m \le 3 \cdot 10^5$$$; $$$nm \le 3 \cdot 10^5$$$) — the number of rows and columns, respectively.

Then $$$n$$$ lines follow, each line contains a string of $$$m$$$ characters. The $$$j$$$-th character in the $$$i$$$-th string is * if the $$$j$$$-th cell in the $$$i$$$-th row is black; otherwise, that character is o.

Output

Print one integer — the sum of values of the board over all $$$2^w$$$ possible ways to paint it, taken modulo $$$998\,244\,353$$$.

Examples

Input

3 4 **oo oo*o **oo

Output

144

Input

3 4 **oo oo** **oo

Output

48

Input

2 2 oo o*

Output

4

Input

1 4 oooo

Output

9

Codeforces (c) Copyright 2010-2021 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: May/06/2021 21:30:21 (i1).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|