#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define P pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) UB(A,x)-LB(A,x)
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
using mint=modint1000000007;
signed main(){
  ll N,n,ans=6;cin>>N;vector<string>S(N),T(N);REP(i,N){cin>>S[i];T[i]=S[i];}n=N*(N-1)/2;
  REP(x,1<<n){
    ll k=x;
    REP(i,N)REP(j,i){
      if(S[i][j]=='-'){T[i][j]='o';T[j][i]='x';if(k%2)swap(T[i][j],T[j][i]);}k/=2;
    }
    vector<P>A(N);REP(i,N)REP(j,N)if(T[i][j]=='x')A[i].F++;REP(i,N)A[i].S=i;
    sort(ALL(A));ll p=0;REP(i,N){if(i==0||A[i].F!=A[i-1].F)p++;if(A[i].S==0)ans=min(ans,p);}
  }
  cout<<ans<<endl;
  return 0;
}