# coding: utf-8

# https://atcoder.jp/contests/abc096/tasks/abc096_c
# 13:17-13:33


def main():
    H, W = map(int, input().split())
    s = [None] * (H+2)
    s[0] = [-1] * (W+2)
    s[-1] = [-1] * (W+2)
    for i in range(1, H+1):
        s[i] = [None] * (W+2)
        s[i][0] = -1
        s[i][-1] = -1
        for j, bw in enumerate(input()):
            s[i][j+1] = 1 if bw == "#" else -1
    
    if H == 1 and W == 1 and s[1][1] == 1:
        return "Yes"
    
    for i in range(1, H+1):
        for j in range(1, W+1):
            if s[i][j] == 1:
                if sum([x for row in s[i-1:i+2] for x in row[j-1:j+2]]) == -7:
                    return "No"
    
    return "Yes"


print(main())
