#include<bits/stdc++.h>
using namespace std;
char ch;
int read(){
    int x=0,f=0;ch=getchar();
    while(!isdigit(ch))f=((ch=='-')?1:0),ch=getchar();
    while(isdigit(ch))x=(x<<3)+(x<<1)+ch-'0',ch=getchar();
    return (f)?-x:x;
}
int ot[40],otp;
void write(int x){
    if(!x)return putchar('0'),void();
    while(x)ot[++otp]=x%10,x/=10;
    while(otp)putchar(ot[otp--]+'0');
    return ;
}
const int maxn=5e2+2;
const int mod=998244353;
int n,m;
char s[maxn][maxn];
int ans;
int poi(int i,int j){return (i-1)*m+j;}
struct UFS{
    int fa[maxn*maxn],siz[maxn*maxn];
    void init(int mx){for(int i=1;i<=mx;i++)fa[i]=i,siz[i]=1;}
    int find(int x){return (fa[x]==x)?x:(fa[x]=find(fa[x]));}
    void merge(int u,int v){
        u=find(u),v=find(v);
        if(siz[u]>siz[v])swap(u,v);
        if(!u||u==v)return ;
        fa[u]=v,siz[v]+=siz[u];
        return ;
    }
}ufs;
void upd(int &x,int v){return ((x+=v)>=mod)?(x-=mod):x,void();}
int main(){
    // freopen("A.in","r",stdin);
    // freopen("A.out","w",stdout);
    n=read(),m=read();
    ufs.init(n*m);
    for(int i=1;i<=n;i++)scanf("%s",s[i]+1);
    ans=1;
    for(int i=1;i<=n;i++){
        for(int j=1,f1,f2;j<=m;j++){
            if(s[i][j]!='#')continue;
            f1=((i>1&&s[i-1][j]=='#')?ufs.find(poi(i-1,j)):0);
            f2=((j>1&&s[i][j-1]=='#')?ufs.find(poi(i,j-1)):0);
            if(!f1||!f2||f1!=f2)ans=4ll*ans%mod;
            else ans=2ll*ans%mod;
            ufs.merge(f1,poi(i,j));
            ufs.merge(f2,poi(i,j));
        }
    }
    write(ans);putchar('\n');
    return 0;
}