#include<bits/stdc++.h>
using namespace std;
int n,m;
char a[101][101];
bool v[101][101];
bool dfs(int x,int y)
{
	if(x<1||y<1||x>n||y>n||a[x][y]=='#'||v[x][y])return 0;
	else if(x==n&&y==m)return 1;
	v[x][y]=1;
	bool k=dfs(x+1,y)||dfs(x-1,y)||dfs(x,y+1)||dfs(x,y-1);
	v[x][y]=0;
	return k;
}
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	for(int j=1;j<=m;j++)
		cin>>a[i][j];
	if(dfs(1,1))cout<<"Yes";
	else cout<<"No";
    return 0;
}