#include<bits/stdc++.h>
using namespace std;
const int N = 1e3 + 5;
int a[N][N];
int dx[4]={0,0,-1,1};
int dy[4]={1,-1,0,0};
string ans[4]={"Yes","No"};
int vis[N][N];
int n , m;
int f(int x,int y){
	//cout<<x<<" "<<y<<endl;
	if(x==n && y==m){
		return 1;
	}
	int flag=0;
	for(int i=0;i<4;++i){
		
		int xx=x+dx[i];
		int yy=y+dy[i];
		if(xx>=0 && xx<=n && yy>=0 && yy<=m && a[xx][yy]==1 && vis[xx][xx]==0){
			vis[xx][yy]=1;
		f(xx,yy);
		
	vis[xx][yy]=0;
		}
	}
	return 0;
	
	
	
}
int main(){

	
	cin >> n >> m;
	
	for(int i = 1 ; i <= n ; ++ i) {
		
		for(int j = 1 ; j <= m ; ++ j) {
			
			char s;
			
			cin >> s;
			
			if(s == '.') {
				a[i][j] = 1;
			}
			
			else {
				a[i][j] = 0;
			}
			
		}
		
	}
	cout<<ans[f(1,1)]; 
	
	
}