#ABC 096 C - Grid Repainting 2
H, W = map(int, input().split())
S = [input() for i in range(H)]

s = [[0] * (W+2) for i in range(H+2)]
for h in range(H):
    for w in range(W):
        s[h+1][w+1] = S[h][w]
print(s)

c = [[0] * (W+2) for i in range(H+2)]
for h in range(1,H+1):
    for w in range(1,W+1):
        if s[h][w] == '#':
            if s[h][w-1] == '#':
                c[h][w] += 1
                c[h][w-1] +=1
            if s[h][w+1] == '#':
                c[h][w] += 1
                c[h][w+1] +=1
            if s[h+1][w] == '#':
                c[h][w] += 1
                c[h+1][w] +=1
            if s[h-1][w] == '#':
                c[h-1][w] += 1
                c[h-1][w] +=1

for h in range(1,H+1):
    for w in range(1,W+1):
        if s[h][w] == '#':
            if c[h][w] == 0:
                print('No')
                exit()
print('Yes')