H, W = map(int, input().split())
S =['.'*(W+2)]+ ['.'+input()+'.' for i in range(H)]+['.'*(W+2)]
print(S)
flag = True
for i in range(1, H+1):
    for k in range(1, W+1):
        if S[i][k] == '#':
            if S[i-1][k] == '.' and S[i+1][k] == '.' and S[i][k+1] == '.' and S[i][k-1] == '.':
                flag = False
                break
    if not flag:
        break
if flag:
    print('Yes')
else:
    print('No')