#include<bits/stdc++.h>
using namespace std;
int n,m;
char c;
bool f[110][110],ff=1;
void dfs(int x,int y){
	if(x<0||y<0||x>n||y>m||f[x][y]) return;
	if(x==n&&y==m){
		ff=0;
		cout<<"YES";
		return;
	}
	f[x][y]=1;
	if(!f[x-1][y]&&ff) dfs(x-1,y);
	if(!f[x+1][y]&&ff) dfs(x+1,y);
	if(!f[x][y-1]&&ff) dfs(x,y-1);
	if(!f[x][y+1]&&ff) dfs(x,y+1);
	f[x][y]=0;
	return;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++){
			cin>>c;
			if(c=='#') f[i][j]=1;
			else f[i][j]=0;
		}
	dfs(1,1);
	if(ff) cout<<"NO";
	return 0;
}