#include<bits/stdc++.h>
using namespace std;
#define nx x+dx[i]
#define ny y+dy[i]
#define int long long
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
const int N=1010,P=998244353;
int v[N][N],a[N][N];int n,m,cnt;
int qpow(int a,int b){int res=1;for(;b;b>>=1,a=a*a%P)if(b&1)res=res*a%P;return res;}
void bfs(int xx,int yy)
{
	deque<pair<int,int>>q;q.push_back({xx,yy});
	a[xx][yy]=cnt;
	while(!q.empty())
	{
		int x=q.front().first,y=q.front().second;q.pop_front();
		for(int i=0;i<4;i++)if(nx>0&&nx<=n&&ny>0&&ny<=m&&v[nx][ny]&&!a[nx][ny])
			q.push_back({nx,ny}),a[nx][ny]=cnt;
	}
}
signed main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		string st;cin>>st;
		for(int j=0;j<m;j++)v[i][j+1]=st[j]=='#';
	}
	for(int i=1;i<=n;i++)for(int j=1;j<=m;j++)
		if(v[i][j]&&!a[i][j])
			cnt++,bfs(i,j);
	int sum=0,ans=0;
	for(int i=1;i<=n;i++)for(int j=1;j<=m;j++)if(!v[i][j])
	{
		int x=i,y=j;
		set<int>s;
		for(int i=0;i<4;i++)if(nx>0&&nx<=n&&ny>0&&ny<=m&&v[nx][ny])
			s.insert(a[nx][ny]);
		int ss=s.size();
		ans+=cnt;
		if(ss==0)ans++;
		if(ss==2)ans--;
		if(ss==3)ans-=2;
		if(ss==4)ans-=3;
		sum++;
	}
	int d=__gcd(sum,ans);sum/=d,ans/=d;ans%=P;
	int anss=ans*qpow(sum,P-2)%P;
	cout<<anss;
	return 0;
}