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