def is_not_isolated(s_list, i, j):
    num_row, num_col = len(s_list), len(s_list[0])
    map_char_to_bool = {'.': False, '#': True}
    if num_row == 1 and num_col == 1:
        return False
    elif num_row == 1:
        if j == 0:
            not_isolated = map_char_to_bool[s_list[0][1]]
        elif j == num_col - 1:
            not_isolated = map_char_to_bool[s_list[0][num_col - 2]]
        else:
            not_isolated = map_char_to_bool[s_list[0][j - 1]]\
                    or map_char_to_bool[s_list[0][j + 1]]
    elif num_col == 1:
        if i == 0:
            not_isolated = map_char_to_bool[s_list[1][0]]
        elif i == num_row - 1:
            not_isolated = map_char_to_bool[s_list[num_row - 2][0]]
        else:
            not_isolated = map_char_to_bool[s_list[i - 1][0]]\
                    or map_char_to_bool[s_list[i + 1][0]]
    else:
        # assuming num_row >= 2 and num_col >= 2
        if i == 0 and j == 0:
            not_isolated = map_char_to_bool[s_list[0][1]]\
                    or map_char_to_bool[s_list[1][0]]
        elif i == 0 and j == num_col - 1:
            not_isolated = map_char_to_bool[s_list[0][num_col - 2]]\
                    or map_char_to_bool[s_list[1][num_col - 1]]
        elif i == num_row - 1 and j == 0:
            not_isolated = map_char_to_bool[s_list[num_row - 2][0]]\
                    or map_char_to_bool[s_list[num_row - 1][1]]
        elif i == num_row - 1 and j == num_col - 1:
            not_isolated = map_char_to_bool[s_list[num_row - 2][num_col - 1]]\
                    or map_char_to_bool[s_list[num_row - 1][num_col - 2]]
        elif i == 0:
            not_isolated = map_char_to_bool[s_list[0][j - 1]]\
                    or map_char_to_bool[s_list[0][j + 1]]\
                    or map_char_to_bool[s_list[1][j]]
        elif i == num_row - 1:
            not_isolated = map_char_to_bool[s_list[num_row - 1][j - 1]]\
                    or map_char_to_bool[s_list[num_row - 1][j + 1]]\
                    or map_char_to_bool[s_list[num_row - 2][j]]
        elif j == 0:
            not_isolated = map_char_to_bool[s_list[i - 1][0]]\
                    or map_char_to_bool[s_list[i + 1][0]]\
                    or map_char_to_bool[s_list[i][1]]
        elif j == num_col - 1:
            not_isolated = map_char_to_bool[s_list[i - 1][num_col - 1]]\
                    or map_char_to_bool[s_list[i + 1][num_col - 1]]\
                    or map_char_to_bool[s_list[i][num_col - 2]]
        else:
            not_isolated = map_char_to_bool[s_list[i][j - 1]]\
                    or map_char_to_bool[s_list[i][j + 1]]\
                    or map_char_to_bool[s_list[i + 1][j]]\
                    or map_char_to_bool[s_list[i + 1][j]]

    return not_isolated


H, W = [int(elem) for elem in input().split(' ')]
s_list = [list(input()) for _ in range(H)]
assert len(s_list) == H
assert len(s_list[0]) == W

for i in range(len(s_list)):
    for j in range(len(s_list[0])):
        if s_list[i][j] == ".":
            continue
        else:
            if not is_not_isolated(s_list, i, j):
                print("No")
                exit(0)
else:
    print("Yes")
