import io
import sys
from collections import defaultdict, deque, Counter
from itertools import permutations, combinations, accumulate
from heapq import heappush, heappop
from bisect import bisect_right, bisect_left
from math import gcd
import math
from sys import stdout

_INPUT = """\
6
3 4
###.
.###
.##.
3 3
#.#
.#.
#.#
10 30
####.####..#######.######.#.#.
###.##.#.##.##.##.######.##..#
.#.#.#.#..######.....#..##.##.
##.#..#.###.###..#.###.#######
##.##.#####.####.#..##.#..####
..#####..###########.##.##.##.
######..#...#####..###..##..##
.###..#.##..#..###..#####...##
###..###########.#..##.#...###
#.##.#####.####.####.####.###.
"""

class UnionFind():
  def __init__(self, n):
    self.n = n
    self.parents = [-1] * n
  def find(self, x):
    if self.parents[x] < 0:
      return x
    else:
      self.parents[x] = self.find(self.parents[x])
      return self.parents[x]
  def union(self, x, y):
    x = self.find(x)
    y = self.find(y)
    if x == y:
      return
    if self.parents[x] > self.parents[y]:
       x, y = y, x
    self.parents[x] += self.parents[y]
    self.parents[y] = x
  def size(self, x):
    return -self.parents[self.find(x)]
  def same(self, x, y):
    return self.find(x) == self.find(y)
  def members(self, x):
    root = self.find(x)
    return [i for i in range(self.n) if self.find(i) == root]
  def roots(self):
    return [i for i, x in enumerate(self.parents) if x < 0]
  def group_count(self):
    return len(self.roots())
  def all_group_members(self):
    return {r: self.members(r) for r in self.roots()}
  def __str__(self):
    return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())

def input():
  return sys.stdin.readline()[:-1]

mod=998244353
def solve(test):
  N,M=map(int, input().split())
  S=[input() for _ in range(N)]
  uf=UnionFind(N*M)
  ans=1
  for i in range(N):
    for j in range(M):
      if S[i][j]=="#":
        if i>0 and S[i-1][j]=="#" and j>0 and S[i][j-1]=="#" and uf.find((i-1)*M+j)==uf.find(i*M+j-1):
          ans=ans*2%mod
        else:
          ans=ans*4%mod
        if i>0 and S[i-1][j]=="#": uf.union((i-1)*M+j,i*M+j)
        if j>0 and S[i][j-1]=="#": uf.union(i*M+j-1,i*M+j)
      # print(i,j,ans)
  print(ans)

def random_input():
  from random import randint,shuffle
  N=randint(1,10)
  M=randint(1,N)
  A=list(range(1,M+1))+[randint(1,M) for _ in range(N-M)]
  shuffle(A)
  return (" ".join(map(str, [N,M]))+"\n"+" ".join(map(str, A))+"\n")*3

def simple_solve():
  return []

def main(test):
  if test==0:
    solve(0)
  elif test==1:
    sys.stdin = io.StringIO(_INPUT)
    case_no=int(input())
    for _ in range(case_no):
      solve(0)
  else:
    for i in range(1000):
      sys.stdin = io.StringIO(random_input())
      x=solve(1)
      y=simple_solve()
      if x!=y:
        print(i,x,y)
        print(*[line for line in sys.stdin],sep='')
        break

#0:提出用、1:与えられたテスト用、2:ストレステスト用
main(0)