H,W  = map(int, input().split()) 
S = [list(input()) for i in range(H)] 
T =[['.']*(W+2)]
for y in range (H):
    T.append(['.']+S[y]+['.'])

T.append(['.']*(W+2))

ans = 'Yes'
for y in range(1,H+1):
    for x in range(1,W+1):
        if ((T[y][x]=='#') and (T[y-1][x-1]=='.') 
            and (T[y+1][x-1]=='.') and (T[y-1][x+1]=='.') and (T[y+1][x+1]=='.') ):
            ans = 'No'

print(ans)
            
            