import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
md = 10**9+7
# md = 998244353

from copy import deepcopy

def start():
    for i in range(h):
        for j, a in enumerate(aa0[i]):
            if aa0[i][j] == 0:
                return i, j

def ok(d):
    def move():
        nonlocal i, j
        di, dj = dij[d]
        ni, nj = i+di, j+dj
        if 0 <= ni < h and 0 <= nj < w and aa[ni][nj] == 0:
            i, j = ni, nj
            aa[i][j] = 2
            return True
        return False

    aa = deepcopy(aa0)
    d0 = d
    right = 0
    i, j = si, sj
    while 1:
        if not move():
            d = (d+1)%4
            if not move():
                if right:
                    return False
                right = 1
                d = (d+2)%4
                if not move():
                    return False
        if (i, j) == (si, sj):break

    for i in range(h):
        for a in aa[i]:
            if a==0:return False

    if right and (d-1)%4==d0:return False

    return True

h, w = LI()
aa0 = [[c == "#" for c in SI()] for _ in range(h)]
si, sj = start()
for d in range(4):
    if ok(d):
        print("YES")
        exit()
print("NO")