h,w=map(int,input().split())
s=[input() for _ in range(h)]


a="YES"

for i in range(h):
    if a=="NO":
        break
    for j in range(w):
        a="NO"
        if s[i][j]==".":
            a="YES"
        else:
            if i-1>=0 and s[i-1][j]=="#":
                a="YES"
            elif j-1>=0 and s[i][j-1]=="#":
                a="YES"
            elif j+1<w and s[i][j+1]=="#":
                a="YES"
            elif i+1<h and s[i+1][j]=="#":
                a="YES"
        if a=="NO":
            break


print(a)

            