Problem:
Score: 300 points

Problem Statement

We have a canvas divided into a grid with H rows and W columns. The square at the i-th row from the top and the j-th column from the left is represented as (i, j).

Initially, all the squares are white. square1001 wants to draw a picture with black paint. His specific objective is to make Square (i, j) black when s_{i, j}= #, and to make Square (i, j) white when s_{i, j}= ..

However, since he is not a good painter, he can only choose two squares that are horizontally or vertically adjacent and paint those squares black, for some number of times (possibly zero). He may choose squares that are already painted black, in which case the color of those squares remain black.

Determine if square1001 can achieve his objective.

Constraints

H is an integer between 1 and 50 (inclusive).

W is an integer between 1 and 50 (inclusive).

For every (i, j) (1 \leq i \leq H, 1 \leq j \leq W), s_{i, j} is # or ..

Input

Input is given from Standard Input in the following format:

H W
s_{1, 1} s_{1, 2} s_{1, 3} ... s_{1, W}
s_{2, 1} s_{2, 2} s_{2, 3} ... s_{2, W}
: :
s_{H, 1} s_{H, 2} s_{H, 3} ... s_{H, W}

Output

If square1001 can achieve his objective, print Yes; if he cannot, print No.

Sample Input 1

3 3
.#.
###
.#.

Sample Output 1

Yes

One possible way to achieve the objective is shown in the figure below. Here, the squares being painted are marked by stars.

Sample Input 2

5 5
#.#.#
.#.#.
#.#.#
.#.#.
#.#.#

Sample Output 2

No

square1001 cannot achieve his objective here.

Sample Input 3

11 11
...#####...
.##.....##.
#..##.##..#
#..##.##..#
#.........#
#...###...#
.#########.
.#.#.#.#.#.
##.#.#.#.##
..##.#.##..
.##..#..##.

Sample Output 3

Yes

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner s = new Scanner(System.in);
		int H = s.nextInt();
		int W = s.nextInt();
		String sl = null;
		String[] sa = new String[W];
		String[][] sda = new String[H][W];

		boolean b = true;

		for (int i = 0; i < H; i++) {
			sl = s.next();
			sa = sl.split("");
			for (int j = 0; j < W; j++) {
				sda[i][j] = sa[j];
			}
		}

		/**/
		for (int h = 0; h < H; h++) {
			for (int w = 0; w < W; w++) {
				if (b) {
					if (sda[h][w].equals("#")) {
						/*100
						000
						000*/
						if (h == 0 && w == 0) {
							if (sda[h][w + 1].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*001
						000
						000*/
						else if (h == 0 && w == W) {
							if (sda[h][w - 1].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						000
						100*/
						else if (h == H && w == 0) {
							if (sda[h - 1][w].equals("#") ||
									sda[h][w + 1].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						000
						001*/
						else if (h == H && w == W) {
							if (sda[h][w - 1].equals("#") ||
									sda[h - 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*010
						000
						000*/
						else if (h == 0) {
							if (sda[h][w - 1].equals("#") ||
									sda[h][w + 1].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						000
						010*/
						else if (h == H) {
							if (sda[h][w - 1].equals("#") ||
									sda[h - 1][w].equals("#") ||
									sda[h][w + 1].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						100
						000*/
						else if (w == 0) {
							if (sda[h - 1][w].equals("#") ||
									sda[h][w + 1].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						001
						000*/
						else if (w == W) {
							if (sda[h][w - 1].equals("#") ||
									sda[h - 1][w].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
						/*000
						010
						000*/
						else {
							if (sda[h][w - 1].equals("#") ||
									sda[h - 1][w].equals("#") ||
									sda[h][w + 1].equals("#") ||
									sda[h + 1][w].equals("#")) {
							} else {
								b = false;
								break;
							}
						}
					}
				}
			}
		}
		String ans = b ? "Yes" : "No";
		System.out.println(ans);
	}

}