#include using namespace std; typedef long long ll; typedef long double ld; typedef pair Pii; typedef pair Pil; typedef pair Pll; typedef pair Pli; typedef vector> Mat; #define fi first #define se second const ll MOD = 1e9 + 7; const ll MOD2 = 998244353; const ll MOD3 = 1812447359; const ll INF = 1ll << 62; const double PI = 2 * asin(1); void yes() { printf("yes\n"); } void no() { printf("no\n"); } void Yes() { printf("Yes\n"); } void No() { printf("No\n"); } void YES() { printf("YES\n"); } void NO() { printf("NO\n"); } int h, w; char c; bool s[405][405]; int dp[805][405][405]; int main() { cin >> h >> w; for (int i = 1; i <= h; i++) { for (int j = 1; j <= w; j++) { cin >> c; if (c == '.') { s[i][j] = true; } } } dp[3][2][1] = 1; for (int i = 4; i <= h + w; i++) { for (int j = max(1, i - h); j <= min(i - 1, w); j++) { for (int k = max(1, i - h); k <= min(i - 1, w); k++) { if (j == k) { continue; } if (!s[i - j][j] || !s[i - k][k]) { continue; } ll now = 0; for (int jj = -1; jj <= 0; jj++) { for (int kk = -1; kk <= 0; kk++) { now += dp[i - 1][j + jj][k + kk]; } } now %= MOD2; dp[i][j][k] = now; } } } cout << dp[h + w - 1][w][w - 1] << endl; return 0; }