# coding: utf-8
# Your code here!
H,W = list(map(int,raw_input().split()))
field = []
answer = "Yes"
for i in range (H):
    li = list(raw_input().strip())
    field.append(li[:])
def check(a,b):
    if field[a][b] ==".":
        return True
    check_li = [[a-1,b],[a+1,b],[a,b+1],[a,b-1]]
    check_li = filter(lambda x: 0 <= x[0] <= H-1 and 0<= x[1] <=W-1,check_li )
    for i in check_li:
        if field[i[0]][i[1]] == "#":
            return True
            break
    else:
        print a,b,field[i[0]][i[1]]
        return False
for i in range (H):
    for j in range (W):
        if check(i,j) == False:
            answer = "No"
            break
print answer




        