#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[8]={1,0,-1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

int main(){
    ll n;cin >> n;
    vector<string> g(n);
    rep(i,n)cin >> g[i];
    rep(i,n){
        if(g[0][i]=='-'){
            g[0][i]='o';
            g[i][0]='x';
        }
    }
    ll win=0;
    rep(i,n)if(g[0][i]=='o')win++;
    ll cnt=0;
    rep(i,n)rep(j,n)if(g[i][j]=='-')cnt++;
    cnt/=2;
    ll ans=inf;
    rep(bit,1<<cnt){
        vector<string> z=g;
        ll now=0;
        rep(i,n)rep(j,n){
            if(z[i][j]=='-'){
                if(bit&(1<<now)){
                    z[i][j]='o';
                    z[j][i]='x';
                }
                else{  
                    z[i][j]='x';
                    z[j][i]='o';
                }
                now++;
            }
        }
        set<ll> st;
        rep(i,n){
            ll ret=0;
            rep(j,n){
                if(g[i][j]=='o')ret++;
            }
            st.insert(ret);
        }
        ll ord=1;
        for(auto p:st)if(win<p)ord++;
        chmin(ans,ord);
    }
    cout << ans <<endl;
}