H, W = map(int, input().split())
A = [input() for _ in range(H)]

answer = 0
perm = [["", 0, 0]]

for _ in range(H+W-2):
    np = []
    for p in perm:
        if p[1] != H-1:
            np.append([p[0]+"D", p[1]+1, p[2]])
        if p[2] != W-1:
            np.append([p[0]+"R", p[1], p[2]+1])
    perm = np

for pattern in perm:
    pattern = pattern[0]
    cnt = 1
    h, w = 0, 0
    for p in pattern:
        if p == "D":
            h += 1
        else:
            w += 1
        if A[h][w] == "#":
            break
        elif A[h][w] == "x":
            cnt -= 1
            if cnt < 0:
                break
        else:
            cnt += 1
    else:
        answer += 1

print(answer)