N, M = map(int, input().split())
S = [int(input().replace("o", "1").replace("x", "0"), 2) for i in range(N)]
ans = 0
for i in range(N):
    if S[i] and all(S[i] & S[j] == 0 for j in range(N) if i != j):
        ans += 1
print(ans)