#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
    int H,W;
    cin>>H>>W;
    vector<string> S(H);
    for(int i=0;i<H;i++) cin>>S[i];
    vector<vector<int>> dp(800,vector<int>(800));
    int n = 800;
    dp[0][1] = 1;
    int mod = 998244353;
    for(int s=2;s<H+W-1;s++){
    	for(int i=s-1;i>=0;i--)for(int j=s-1;j>i;j--){
    		dp[i][j+1] += dp[i][j];
    		if(i+1 != j || s == H+W-2) dp[i+1][j] += dp[i][j];
    		dp[i+1][j+1] += dp[i][j];
    	}
    	for(int i=s;i>=0;i--)for(int j=s;j>i;j--){
    		dp[i][j] %= mod;
    		if(s == H+W-2) continue;
    		if(i < 0 || H <= i || s-i < 0 || W <= s-i || S[i][s-i] == '#') dp[i][j] = 0;
    		if(j < 0 || H <= j || s-j < 0 || W <= s-j || S[j][s-j] == '#') dp[i][j] = 0;
    	}
    }
    cout<<dp[H-1][H-1]<<endl;
}