h,w=map(int,input().split())

s=[input() for _ in range(h)]

dx=[1,0,-1,0]
dy=[0,1,0,-1]

for i in range(h):
    for j in range(w):
        if(s[i][j]=='.'):continue
        f=False
        for k in range(4):
            ni=i+dx[k]
            nj=j+dy[k]
            if(0<=ni<=h-1 and 0<=nj<=w-1):
                if(s[ni][nj]=='#'):f=True
        if(not f):
            print(i,j)
            print("No")
            exit()
print("Yes")