N, M = map(int, input().split())
S = [input() for _ in range(N)]

cnt = [0]*M
for s in S:
    for i, n in enumerate(s):
        if n == "o":
            cnt[i] += 1

ans = 0
for s in S:
    flag = False
    for i, n in enumerate(s):
        if n == "o":
            flag = True
            if cnt[i] != 1:
                break
    else:
        ans += flag

print(ans)