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

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

def dfs(i, j, d, r):
    if i == si and j == sj and aa[i][j]:
        for i in range(h):
            for a in aa[i]:
                if a == 0: return False
        if r and (d-1)%4 == d0: return False
        return True

    di, dj = dij[d]
    ni, nj = i+di, j+dj
    if 0 <= ni < h and 0 <= nj < w and aa[ni][nj] == 0:
        aa[ni][nj] = 1
        if dfs(ni, nj, d, r): return True
        aa[ni][nj] = 0
    else:
        d = (d+1)%4
        di, dj = dij[d]
        ni, nj = i+di, j+dj
        if 0 <= ni < h and 0 <= nj < w and aa[ni][nj] == 0:
            aa[ni][nj] = 1
            if dfs(ni, nj, d, r): return True
            aa[ni][nj] = 0

        d = (d+2)%4
        di, dj = dij[d]
        ni, nj = i+di, j+dj
        if 0 <= ni < h and 0 <= nj < w and aa[ni][nj] == 0 and r == 0:
            aa[ni][nj] = 1
            if dfs(ni, nj, d, 1): return True
            aa[ni][nj] = 0
    return False

h, w = LI()
aa = [[c == "#" for c in SI()] for _ in range(h)]
si, sj = start()
for d0 in range(4):
    if dfs(si, sj, d0, 0):
        print("YES")
        exit()
print("NO")