H, W = map(int, input().split())
S = [input() for _ in range(H)]

for i in range(H):
    S[i] = '.' + S[i] + '.'
S = ['.' * (W + 2)] + S + ['.' * (W + 2)]

cnt_list = []
for i in range(1,H+1):
    for j in range(1, W+1):
        if S[i][j] == '.':
            pass
        else:
            ser = S[i-1][j] + S[i][j-1] + S[i][j+1] + S[i+1][j] + S[i+1][j+1]
            cnt_list.append(ser.count('#'))
if 0 in cnt_list:
    print('No')
else:
    print('Yes')