R=range
I=input
J=lambda:list(map(int,I().split()))
N,M=J()
S=[I()for i in R(N)]
S=[sum((s[j]=='o')<<j for j in R(M))for s in S]
print(sum(1 for i in R(N)if S[i]and all(S[i]&S[j]<1for j in R(N)if i^j)))