#include<bits/stdc++.h>
using lint=long long;
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint n;std::cin>>n;
    std::vector<std::string>a(n);
    for(auto&&s:a)std::cin>>s;
    lint N=1l<<n*(n-1)/2;
    lint ans=n;
    for(lint bs=0;bs<N;bs++){
        std::vector<std::vector<lint>>b(n,std::vector<lint>(n));
        for(lint i=0,k=0;i<n;i++){
            for(lint j=i+1;j<n;j++,k++){
                char c=a.at(i).at(j);
                b.at(i).at(j)=c=='-'?bs>>i&1:c=='o';
                b.at(j).at(i)=!b.at(i).at(j);
            }
        }
        lint win=0;
        std::vector<lint>ckd(n+1);
        for(lint i=0;i<n;i++){
            lint x=std::accumulate(b.at(i).begin(),b.at(i).end(),0ll);
            if(i==0)win=x;
            ckd.at(x)=true;
        }
        lint now=std::count(ckd.begin()+win,ckd.end(),true);
        if(now<ans)ans=now;
    }
    std::cout<<ans<<'\n';
}