H,W = map(int,input().split())
grid = [[]] * H

for i in range(H):
  c = list(input())
  grid[i] = c
  
black = "#"
white = "."

ans = "Yes"

for i in range(H):
  for j in range(W):
    if grid[i][j] == black:
      around = ""
      for k in range(max(0, i - 1),min(W - 1,i + 2)):
        if k != j:
          around += grid[i][k]
      for t in range(max(0, j - 1),min(H - 1,j + 2)):
        if t != i:
          around += grid[t][j]
      
      if all([s == white for s in around]):
        ans = "No"
        break
  if ans == "No":
    break
      
print(ans)
