#include <iostream>
#include <stdio.h>
using namespace std;

bool qiang[110][110] = {false};
bool dfsUsed[110][110] = {false};

bool used[110][110][4] = {false};

bool zdrkl = false;//找到入口了
int rkX, rkY, rkFx;

int offset[4][2] = {{1, 0}, {0, -1}, {-1, 0}, {0, 1}};

int N, M;

bool isCourTYard(int x, int y){
	if(x > 0 && y > 0 && !qiang[x-1][y] && !qiang[x][y-1] && !qiang[x-1][y-1]) return true;
	if(x > 0 && y <= M && !qiang[x-1][y] && !qiang[x][y+1] && !qiang[x-1][y+1]) return true;
	if(x <= N && y > 0 && !qiang[x+1][y] && !qiang[x][y-1] && !qiang[x+1][y-1]) return true;
	if(x <= N && y <= M && !qiang[x+1][y] && !qiang[x][y+1] && !qiang[x+1][y+1]) return true;
	return false;
}

bool dfs(int x, int y){
	if(zdrkl) return true;
	if(x > 0 && x <= N && qiang[x-1][y] && qiang[x+1][y]){
		zdrkl = true;
		rkX = x;
		rkY = y;
		if(y > 0 && dfsUsed[x][y-1]) rkFx = 1;
		else rkFx = 3;
		return true;
	}
	if(y > 0 && y <= M && qiang[x][y-1] && qiang[x][y+1]){
		zdrkl = true;
		rkX = x;
		rkY = y;
		if(x > 0 && dfsUsed[x-1][y]) rkFx = 2;
		else rkFx = 0;
	}
	dfsUsed[x][y] = 1;
	if(x > 0 && !qiang[x-1][y] && !dfsUsed[x-1][y]){
		if(dfs(x-1, y)) return true;
	}
	if(x <= N && !qiang[x+1][y] && !dfsUsed[x+1][y]){
		if(dfs(x+1, y)) return true;
	}
	if(y > 0 && !qiang[x][y-1] && !dfsUsed[x][y-1]){
		if(dfs(x, y-1)) return true;
	}
	if(y <= M && !qiang[x][y+1] && !dfsUsed[x][y+1]){
		if(dfs(x, y+1)) return true;
	}
	return false;
}

int main() {
	scanf("%d%d", &N, &M);
	char s[200];
	for(int i = 1; i <= N; i++){
		scanf("%s", s);
		for(int j = 1; j <= M; j++){
			char c = s[j-1];
			if(c == '#') qiang[i][j] = true;
		}
	}
	dfs(0,0);
	//cout << rkX << " " << rkY << " " << rkFx;
	int fx = rkFx, x = rkX, y = rkY;
	while(1){
		//cout << x << " " << y << " " << fx << endl;
		int FX;
		for(FX = (fx+1)%4; ; FX = (FX+1)%4){
			if(!qiang[x+offset[FX][0]][y+offset[FX][1]]) break;
		}
		if(used[x][y][FX]){
			printf("NO\n");
			return 0;
		}
		used[x][y][FX] = true;
		fx = (FX+2)%4;
		x += offset[FX][0];
		y += offset[FX][1];
		//cout << x << " " << y << " " << fx << endl;
		if(x == rkX && y == rkY){
			printf("NO\n");
			return 0;
		}
		if(isCourTYard(x, y)){
			printf("YES\n");
			return 0;
		}
	}
	return 0;
}