#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
int main () {
	int H, W;
	cin >> H >> W;
	assert(1 <= min(H, W) && max(H, W) <= 500);
	mint ans = 1;
	char A[555][555];
	for (int i = 0; i <= H; i ++) {
		for (int j = 0; j <= W; j ++) {
			if (min(i, j) == 0) {
				A[i][j] = '.';
			} else {
				cin >> A[i][j];
				if (A[i][j] == '#') {
					ans *= 2;
					if (A[i][j - 1] == '.' || A[i - 1][j] == '.') {
						ans *= 2;
					}
					if (A[i][j - 1] == '.' && A[i - 1][j] == '.') {
						ans *= 2;
					}
				}
			}
		}
	}
	for (int i = 1; i <= H; i ++) {
		A[i][W + 1] = '.';
	}
	for (int j = 1; j <= W; j ++) {
		A[H + 1][W] = '.';
	}
	int mi[] = {0, 1, 0, -1}, mj[] = {1, 0, -1, 0};
	for (int i = 1; i <= H; i ++) {
		for (int j = 1; j <= W; j ++) {
			if (A[i][j] == '#') {
				ans /= 2;
				std::stack<pair<int, int>> st ;
				st.emplace(i, j);
				A[i][j] = '.';
				while (!st.empty()) {
					auto [ui, uj] = st.top();
					st.pop();
					for (int d = 0; d < 4; d ++) {
						int vi = ui + mi[d], vj = uj + mj[d];
						if (A[vi][vj] == '#') {
							A[vi][vj] = '.';
							st.emplace(vi, vj);
						}
					}
				}
			}
		}
	}
	cout << ans.val() << endl;
}