import sys

def is_black_in_four_dir(char_list, pos):
    for p in ((1, 0), (-1, 0), (0, 1), (0, -1)):
        if square_list[pos[1]+p[1]][pos[0]+p[0]] == "#":
            return True
    return False

h, w = map(lambda x: int(x), input().split(" "))
square_list = [input() for i in range(h)]

square_list = ["."*(w+2)] + ["." + s + "." for s in square_list] + ["."*(w+2)]

print(square_list)

for y in range(1, h+2):
    for x in range(1, w+2):
        if square_list[y][x] == "#":
            if not is_black_in_four_dir(square_list, (x, y)):
                print("No")
                sys.exit()
    
print("Yes")