H, W = map(int, input().split())
S = [input() for i in range(H)]

dp = [[0 for i in range(H)] for j in range(H)]
dp[0][0] = 1

di, dj = [1, 0], [0, 1]

MOD = 998244353

for k in range(0, H+W-2):
	ndp = [[0 for i in range(H)] for j in range(H)]
	for ai in range(H):
		for bi in range(H):
			aj = k - ai
			bj = k - bi
			#Alice : (ai, aj), Bob : (bi, bj)
			for x in range(2):
				for y in range(2):
					#被る移動は行えない
					nai, naj = ai + di[x], aj + dj[x]
					nbi, nbj = bi + di[y], bj + dj[y]
					if 0 <= nai < H and 0 <= naj < W and 0 <= nbi < H and 0 <= nbj < W and S[nai][naj] == '.' and S[nbi][nbj] == '.' and (k == H+W-3 or nai != nbi or naj != nbj):
						ndp[nai][nbi] += dp[ai][bi]
						ndp[nai][nbi] %= MOD
	dp, ndp = ndp, dp
	# print(dp)
print(dp[-1][-1]*pow(2, -1, MOD)%MOD)