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No
 No
 No
 Yes
 Yes
 No
 Yes
 Yes
 Yes
 No
 Yes
 No
 No
 Yes
 No
 Yes
 No
 No
 Yes
 No
 No
 No

import sys
n,m = raw_input().strip().split(' ')
sys.setrecursionlimit(50*50*50)
n=int(n)
m=int(m)
x=[]
vis=[]
f=True
coun=0
xl=[0]*n
yl=[0]*m
def itis(xc,yc):
	# global coun
	xl[xc]=1
	yl[yc]=1
	vis[xc][yc]=coun
	# print(xc,yc,coun,n,m)
	for i in range(0,n):
		if (vis[i][yc]==0) and (x[i][yc]=='#'):
			itis(i,yc)
	for i in range(0,m):
		if (vis[xc][i]==0) and (x[xc][i]=='#'):
			itis(xc,i)


for i in range(0,n):
	vis.append([0]*m)
	y=raw_input().strip()
	x.append(y)

for i in range(0,n):
	for j in range(0,m):
		if x[i][j]=='#' and vis[i][j]==0:
			# global coun
			coun+=1
			# print(i,j)
			itis(i,j)
			# print(xl,yl)
			for xc in range(0,n):
				for yc in range(0,m):
					if (xl[xc]==1 and yl[yc]==1 and x[xc][yc]!='#'):
						# global f
						f=False
						break
				xl[xc]=0
			for yc in range(0,m):
				yl[yc]=0
		if not f:
			break
	if not f:
			break
if f:
	print("Yes")
else:
	print("No")
