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No
 No
 No
 Yes
 Yes
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 Yes
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 No
 No


def process(a,r,c):
    row,col= [0]*r,[0]*c 
    dic={}
    for i in xrange(r):
        s= a[i]
        l=''
        for j in xrange(c):
            if s[j]=='#':
                if l: l=l+','+str(j)
                else: l=str(j)
        if not l: continue   
        b=0
        for k in dic:
            if dic[k]==l: 
                b=1 
                nk= k+','+str(i)
                del dic[k]
                dic[nk]=l 
                break 
        if b==0: dic[str(i)]=l 
    #print dic 
    if not dic: return 1 
    for ke in dic:
        k,v=ke,dic[ke]
        rowarr,colarr=map(int,k.split(',')), map(int,v.split(','))
        #print rowarr,colarr
        for x in xrange(len(rowarr)):
            if not 0<=rowarr[x]<=r-1: continue
            if row[rowarr[x]]==1: return 0
            else: row[rowarr[x]]=1 
        for y in xrange(len(colarr)):
            if not 0<=colarr[y]<=c-1: continue
            if col[colarr[y]]==1: return 0
            else: col[colarr[y]]=1 
    return 1 

r,c= map(int,raw_input().split())
a= ['' for _ in xrange(r)]
for i in xrange(r): a[i]= str(raw_input())
if process(a,r,c): print "Yes"
else: print "No"
