#include<iostream>
#include<cassert>
#include<atcoder/modint>
#include<atcoder/dsu>
using namespace std;
using mint=atcoder::modint998244353;
int N,M;
string S[500];
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin>>N>>M;
	int cnt=0;
	for(int i=0;i<N;i++)
	{
		cin>>S[i];
		for(int j=0;j<M;j++)if(S[i][j]=='#')cnt+=2;
	}
	atcoder::dsu uf(N*M);
	for(int i=0;i<N;i++)for(int j=0;j<M;j++)if(S[i][j]=='#')
	{
		int id=i*M+j;
		if(i+1<N&&S[i+1][j]=='#')
		{
			if(!uf.same(id,id+M))uf.merge(id,id+M);
			else cnt--;
		}
		if(j+1<M&&S[i][j+1]=='#')
		{
			if(!uf.same(id,id+1))uf.merge(id,id+1);
			else cnt--;
		}
	}
	cout<<mint(2).pow(cnt).val()<<endl;
}