import itertools

H,W = map(int,input().split())
S = [list(input()) for _ in range(H)]

ok = True        
for i in range(H):
  for j in range(W):
    if S[i][j] == '#':
      for x,y in itertools.product([-1,0,1],repeat=2):
        if not (abs(x) + abs(y) == 1):
          continue
        nx = i + x;ny = j + y
        if 0 <= nx < H and 0 <= ny < W:
          if S[nx][ny] == '.':
            ok = False
            break
if ok:
  print('Yes')
else:
  print('No')
