#include <bits/stdc++.h> #include <atcoder/all> using namespace std; using namespace atcoder; #define rep(i, a, n) for(ll i = a; i < n; i++) #define rrep(i, a, n) for(int i = a; i >= n; i--) #define inr(l, x, r) (l <= x && x < r) #define ll long long #define ld long double // using mint = modint1000000007; using mint = modint998244353; constexpr int IINF = 1001001001; constexpr ll INF = 1e18; template<class t,class u> void chmax(t&a,u b){if(a<b)a=b;} template<class t,class u> void chmin(t&a,u b){if(b<a)a=b;} int main(){ int h, w; cin >> h >> w; vector<string> s(h); rep(i, 0, h) cin >> s[i]; vector<vector<mint>> dp(h+1, vector<mint>(h+1)); dp[2][1] = 1; rep(i, 3, h+w){ vector<vector<mint>> ndp(h+1, vector<mint>(h+1)); rep(j, 1, i){ if(!inr(1, j, h+1) || !inr(1, i-j, w+1)) continue; rep(k, 1, i){ if(!inr(1, k, h+1) || !inr(1, i-k, w+1)) continue; if(j == k) continue; // if(s[k-1][i-k-1] == '#') continue; if(i-j < w && s[j-1][i-j] != '#' && i-k < w && s[k-1][i-k] != '#') ndp[j][k] += dp[j][k]; if(i-j < w && s[j-1][i-j] != '#' && k < h && s[k][i-k-1] != '#') ndp[j][k+1] += dp[j][k]; if(j < h && s[j][i-j-1] != '#' && i-k < w && s[k-1][i-k] != '#') ndp[j+1][k] += dp[j][k]; if(j < h && s[j][i-j-1] != '#' && k < h && s[k][i-k-1] != '#') ndp[j+1][k+1] += dp[j][k]; } } swap(ndp, dp); } cout << dp[h][h].val() << endl; return 0; }