import numpy as np

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

s=np.zeros((H+2,W+2),dtype=int)
s1=s
s2=s
s3=s
s4=s

for i in range(H):
    s0=input()
    for j in range(W):
        if s0[j]==".":
            num=0
        elif s0[j]=="#":
            num=1
        
        s[i+1][j+1]=num
        s1[i+1][j]=num
        s2[i][j+1]=num
        s3[i+1][j+2]=num
        s4[i+2][j+1]=num
        
s=s+s1+s2+s3+s4
ans_s=s[1:H+1,1:W+1]

ans=np.count_nonzero(ans_s==1)


if ans==0:
    print("Yes")
else:
    print("No")