#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<string> s(n);
  rep(i, n) cin >> s[i];
  mint ans = 1;
  dsu uf(n * m);
  rep(i, n) rep(j, m) if (s[i][j] == '#') {
    if (i && s[i-1][j] == '#' && j && s[i][j-1] == '#' && uf.same((i - 1) * m + j, i * m + j - 1)) {
      ans *= 2;
    } else {
      ans *= 4;
    }
    if (i && s[i-1][j] == '#') uf.merge(i * m + j, (i - 1) * m + j);
    if (j && s[i][j-1] == '#') uf.merge(i * m + j, i * m + j - 1);
  }
  cout << ans.val() << '\n';
}