#include <stdio.h>

const int Mod = 998244353;

long long div_mod(long long x, long long y, long long z)
{
	if (x % y == 0) return x / y;
	else return (div_mod((1 + x / y) * y - x, (z % y), y) * z + x) / y;
}

long long pow_mod(int n, long long k)
{
	long long N, ans = 1;
	for (N = n; k > 0; k >>= 1, N = N * N % Mod) if (k & 1) ans = ans * N % Mod;
	return ans;
}

int main()
{
	int i, N, M;
	char S[502][502] = {};
	scanf("%d %d", &N, &M);
	for (i = 1; i <= N; i++) scanf("%s", &(S[i][1]));
	
	int j, n = 0, m = 0;
	for (i = 1; i <= N; i++) {
		for (j = 1; j <= M; j++) {
			if (S[i][j] != '#') continue;
			n++;
			if (S[i][j+1] == '#') m++;
			if (S[i+1][j] == '#') m++;
		}
	}
	
	int ii, jj, k = 0, flag[502][502] = {}, q[250001][2], head, tail;
	for (ii = 1; ii <= N; ii++) {
		for (jj = 1; jj <= M; jj++) {
			if (S[ii][jj] != '#' || flag[ii][jj] != 0) continue;
			flag[ii][jj] = ++k;
			q[0][0] = ii;
			q[0][1] = jj;
			for (head = 0, tail = 1; head < tail; head++) {
				i = q[head][0];
				j = q[head][1];
				if (S[i-1][j] == '#' && flag[i-1][j] == 0) {
					flag[i-1][j] = k;
					q[tail][0] = i - 1;
					q[tail++][1] = j;
				}
				if (S[i+1][j] == '#' && flag[i+1][j] == 0) {
					flag[i+1][j] = k;
					q[tail][0] = i + 1;
					q[tail++][1] = j;
				}
				if (S[i][j-1] == '#' && flag[i][j-1] == 0) {
					flag[i][j-1] = k;
					q[tail][0] = i;
					q[tail++][1] = j - 1;
				}
				if (S[i][j+1] == '#' && flag[i][j+1] == 0) {
					flag[i][j+1] = k;
					q[tail][0] = i;
					q[tail++][1] = j + 1;
				}
			}
		}
	}
	printf("%lld\n", div_mod(pow_mod(4, n), pow_mod(2, m + k - n), Mod));
	fflush(stdout);
	return 0;
}