#include<bits/stdc++.h>
using namespace std;
int n,m;
int b[110][110];char a[110][110];
int heng[5]={0,0,-1,0,1};
int shu[5]={0,-1,0,1,0};
void dfs(int x,int y){
	for(int i=1;i<=4;i++){
		if(x+heng[i]<=n&&x+heng[i]>=1&&y+shu[i]<=m&&y+shu[i]>=1){
		if(a[x+heng[i]][y+shu[i]]=='.'&&b[x+heng[i]][y+shu[i]]==0){
			b[x+heng[i]][y+shu[i]]=1;
			dfs(x+heng[i],y+shu[i]);
			return;
		}
		}
	}return ;
}
int main(){
	
	cin>>n>>m;
	
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>a[i][j];
			b[i][j]=0;
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(a[i][j]=='.'){
				dfs(i,j);
			}
		}
	}
	if(b[n][m]==1){
		cout<<"Yes";
	} else cout<<"No";
	
	return 0;
}