H, W = map(int, input().split())


D=0
Numlist = []
for i in range(H):
	D+=10
	I=0
	RawList = []
	RawList = list(input())

	for j in range(W):
		CheckNum = RawList[j]
		I+=1

		if CheckNum == "#":
			Numlist.append(D+I)

N=0
for k in range(len(Numlist)):
	A = Numlist[k]

	OK=0

	if (A+1) in Numlist:
		OK+=1
	if (A-1) in Numlist:
		OK+=1
	if (A+10) in Numlist:
		OK+=1
	if (A-10) in Numlist:
		OK+=1

	if OK == 0:
		print("No")
		N=1
		break

if N==0:
	print("Yes")


