#ifdef NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<int(n); i++)
const i64 INF = 1001001001001001001;
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
#include <atcoder/modint>
#include <atcoder/dsu>
using Modint = atcoder::static_modint<998244353>;
using namespace std;

void testcase(){
    int H, W; cin >> H >> W;
    vector<string> A(H);
    rep(y,H) cin >> A[y];
    int c = 0;
    int d = 0;
    rep(y,H) rep(x,W) if(A[y][x] == '#') c++;
    rep(y,H-1) rep(x,W-1){
        bool f = true;
        rep(t,2) rep(s,2) if(A[y+t][x+s] != '#') f = false;
        if(f) d++;
    }
    auto dsu = atcoder::dsu(H*W+1);
    rep(y,H) dsu.merge(H*W, y*W);
    rep(y,H) dsu.merge(H*W, y*W+W-1);
    rep(x,W) dsu.merge(H*W, x);
    rep(x,W) dsu.merge(H*W, (H-1)*W+x);
    rep(y,H) rep(x,W-1) if(A[y][x] == '.' && A[y][x+1] == '.') dsu.merge(y*W+x, y*W+x+1);
    rep(y,H-1) rep(x,W) if(A[y][x] == '.' && A[y+1][x] == '.') dsu.merge(y*W+x, y*W+x+W);
    rep(y,H-1) rep(x,W-1) if(A[y][x+1] == '.' && A[y+1][x] == '.') dsu.merge(y*W+x+1, y*W+x+W);
    rep(y,H-1) rep(x,W-1) if(A[y][x] == '.' && A[y+1][x+1] == '.') dsu.merge(y*W+x, y*W+x+1+W);
    rep(y,H) rep(x,W) if(dsu.leader(y*W+x) == y*W+x && A[y][x] == '.' && !dsu.same(H*W, y*W+x)) d++;
    auto ans = Modint(2).pow(c*2-d);
    cout << ans.val() << endl;
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    testcase();
    return 0;
}