import numpy as np
h, w = map(int, input().split())
square = np.array([list(input()) for i in range(h)]).ravel()=="#"
def main():
    for i in range(h*w):
        if square[i] == True:
            flag = 0
            if i // w == 0:
                if square[i+w] == True:
                    flag += 1
            elif i // w == h-1:
                if square[i-w] == True:
                    flag += 1
            else:
                if square[i+w] + square[i-w] == True:
                    flag += 1
            if i % w == 0:
                if square[i+1] == True:
                    flag += 1
            elif i % w == w-1:
                if square[i-1] == True:
                    flag += 1
            else:
                if square[i+1] + square[i-1] == True:
                    flag += 1
            if flag == 0:
                print("No")
                print(i)
                return 0
    print("Yes")
main()