
def GridRepainting():
    H, W = map(int, input().split())
    strlist = []
    for _ in range(0, H):
        strlist.append(list(input()))
    for i in range(0, H):
        for j in range(0, W):
            if strlist[i][j] == '#':
                flag = False
                for x in range(-1, 2):
                    if i + x == -1 or i + x == H:continue
                    for y in range(-1, 2):
                        if j + y == -1 or j + y == W:continue
                        if x == 0 and y == 0:continue
                        if strlist[i + x][j + y] == '#':
                            flag = True
                if flag == False:
                    print('No')
                    return()
    print('Yes')
    return()

GridRepainting()
