#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;

template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}
template <int m> istream& operator>>(istream& is, static_modint<m>& a) {long long x; is >> x; a = x; return is;}
template <int m> istream& operator>>(istream& is, dynamic_modint<m>& a) {long long x; is >> x; a = x; return is;}
template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}
template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;}
template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}
template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}

template<typename T> void chmin(T& a, T b){a = min(a, b);}
template<typename T> void chmax(T& a, T b){a = max(a, b);}

using mint = modint998244353;

int main(){
	int h, w;
	cin >> h >> w;
	vector<string> s(h);
	cin >> s;
	
	vector<vector<mint>> dp(h + 1, vector<mint>(h + 1));
	for(int y = 0; y < h; y++){
		if(s[y][0] == '#') break;
		dp[0][y] = 1;
	}
	auto get_next = [&](int y, int x){
		for(int z = y; z < h; z++) if(s[z][x] == '#') return z;
		return h;
	};
	for(int x = 1; x < w; x++){
		vector<vector<mint>> dp_old(h + 1, vector<mint>(h + 1));
		swap(dp, dp_old);
		int na = get_next(0, x);
		for(int a = 0; a < h; a++){
			if(a == na){
				na = get_next(a + 1, x);
				continue;
			}
			int nb = get_next(a, x);
			for(int b = a + 1; b < h; b++){
				if(b == nb){
					nb = get_next(b + 1, x);
					continue;
				}
				mint val = dp_old[a][b];
				dp[a][b] += val;
				dp[min(na, b)][b] -= val;
				dp[a][nb] -= val;
				dp[min(na, b)][nb] += val;
			}
		}
		for(int a = 0; a < h; a++){
			for(int b = 0; b < h; b++){
				dp[a][b + 1] += dp[a][b];
			}
		}
		for(int a = 0; a < h; a++){
			for(int b = 0; b < h; b++){
				dp[a + 1][b] += dp[a][b];
			}
		}
	}
	cout << dp[h - 2][h - 1] << "\n";
	
	return 0;
}