Problem: You have a large rectangular board which is divided into n × 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 ≤ n, m ≤ 3 ⋅ 10^5; nm ≤ 3 ⋅ 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

Solution (in PYTHON3):

Solution:
# thanks for explaining this DP solution to me moo.
import sys
input = sys.stdin.readline

mod = 998244353

n,m  = map(int,input().split())
board = [input().strip() for i in range(n)]

ans = 0
tot_c = 0
tot_h = []
tot_v = []

for i in range(n):
    for j in range(m):
        if board[i][j] == 'o':
            tot_c += 1

for i in range(n):
    for j in range(m):
        if board[i][j] == 'o' and (j == 0 or board[i][j-1] == '*'):
            tot_h.append(1)
        elif board[i][j] == 'o':
            tot_h[-1] += 1

for j in range(m):
    for i in range(n):
        if board[i][j] == 'o' and (i == 0 or board[i-1][j] == '*'):
            tot_v.append(1)
        elif board[i][j] == 'o':
            tot_v[-1] += 1

# paired[j][i] -> colorings where # of 1's after last 0 % 2 == j
paired = [[0]*(max(n,m)+1) for i in range(2)]
paired[0][1] = paired[1][1] = 1
for i in range(2,max(n,m)+1):
    paired[0][i] = (2*paired[1][i-1] + paired[0][i-1]) % mod
    paired[1][i] = paired[0][i-1]

# dp[i] = sum of dominoes for every maximal tiling of a coloring of i consecutive o's
# with 1's or 0's where we can place a domino at a 1 and not at a 0
dp = [0]*(max(n,m)+1)
for i in range(2,max(n,m)+1):
    dp[i] = (2*dp[i-1] + paired[1][i-1]) % mod
    # we add paired[i][i-1] because this is the extra domino from placing a 1
    # there is no overcount because we always pair as soon as possible (two free 1's) (this restriction is enough)

# find the "contribution" (sum of values) of every consecutive sequence of o's in every
# row and col individually then multiply this by the number of ways to tile the other cells
# not in this row/col (2^everything else)
for num_consec in tot_h + tot_v:
    ans = (ans + dp[num_consec]*pow(2,tot_c-num_consec,mod)) % mod

print(ans)