h, w = [int() for x in input().split()]

point = []

for i in range(h):
  l = input().split()
  for j in range(w):
    if l[j] == "#":
      point.append([i, j])

dp = [[1 for x in range(w * 2 - 1)] for x in range(h)]

center = w - 1
dp[0][center] = 0

count = h * w - 1

for y in range(h):
  for x in range(w * 2 - 1):
    if dp[y][x] == 1:
      for p in point:
        if [p[0] + y, p[1] + x - w + 1] not in point:
          dp[y][x] = 0
          count -= 1

if count > 0:
  print("YES")
else:
  print("NO")