#include<bits/stdc++.h>

using namespace std;
bool mapp[111][111];
int dir[4][2] = {
	1,0,
	0,1,
	-1,0,
	0,-1
};
bool flagg;
int n,m;
void dfs(int x,int y){
	if(x == n && y == m)
		flagg = 1;
	if(flagg)
		return;
	for(int i = 0;i < 4;i++){
		int xx = x + dir[i][0],
			yy = y + dir[i][1];
		if(xx > 0 && xx <= n && yy > 0 && yy <= m && mapp[xx][yy]){
			if(mapp[xx][yy] == 0)
				return;
			mapp[xx][yy] = 0;
			dfs(xx,yy);
			mapp[xx][yy] = 1;
		}
	}
	return;
}
signed main(){
	//step 1. 读题、声明变量
	
	//step 2. 输入
	cin >> n >> m;
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= m;j++){
			char a; 
			cin >> a;
			if(a == '.')
				mapp[i][j] = 1;
			else
				mapp[i][j] = 0; 
		}
	}
	//step 3. 处理
	if(mapp[1][1] == 0)
		return 0;
	if(mapp[n][m] == 0)
		return 0;
	dfs(1,1);
	//step 4. 输出
	if(flagg)
		cout << "Yes";
	else
		cout << "No";
	return 0;
}