#include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
// #define int ll
using PII = pair<int, int>;
 
#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()
 
template<typename T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = max(a, b); }
template<typename T> bool IN(T a, T b, T x) { return a<=x&&x<b; }
template<typename T> T ceil(T a, T b) { return a/b + !!(a%b); }
 
template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) { 
  return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type
fill_v(T &t, const V &v) { t=v; }
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type
fill_v(T &t, const V &v ) { for(auto &e:t) fill_v(e,v); }
 
template<class S,class T>
ostream &operator <<(ostream& out,const pair<S,T>& a){
  out<<'('<<a.first<<','<<a.second<<')'; return out;
}
template<typename T>
istream& operator >> (istream& is, vector<T>& vec){
  for(T& x: vec) {is >> x;} return is;
}
template<class T>
ostream &operator <<(ostream& out,const vector<T>& a){
  out<<'['; for(T i: a) {out<<i<<',';} out<<']'; return out;
}
 
int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0}; // DRUL
const int INF = 1<<30;
const ll LLINF = 1LL<<60;
ll MOD = 1000000007;

signed main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);

  while(1) {
    int n;
    cin >> n;
    if(n == 0) break;
    vector<string> s(n);
    REP(i, n) cin >> s[i];

    auto func = [](vector<char> v) {
      int cnt = 0, ret = 0;
      REP(i, v.size()) {
        if(v[i] == '1') {
          cnt++;
        } else {
          cnt = 0;
        }
        chmax(ret, cnt);
      }
      return ret;
    };

    int ret = 0;
    REP(i, n) {
      vector<char> v;
      REP(j, n) v.push_back(s[i][j]);
      chmax(ret, func(v));
    }
    REP(i, n) {
      vector<char> v;
      REP(j, n) v.push_back(s[j][i]);
      chmax(ret, func(v));
    }
    REP(i, n) {
      vector<char> v;
      int y = 0, x = i;
      while(IN(0,n,x) && IN(0,n,y)) {
        v.push_back(s[y][x]);
        y++, x--;
      }
      chmax(ret, func(v));
    }
    REP(i, n) {
      vector<char> v;
      int y = i, x = n-1;
      while(IN(0,n,x) && IN(0,n,y)) {
        v.push_back(s[y][x]);
        y++, x--;
      }
      chmax(ret, func(v));
    }
    REP(i, n) {
      vector<char> v;
      int y = 0, x = i;
      while(IN(0,n,x) && IN(0,n,y)) {
        v.push_back(s[y][x]);
        y++, x++;
      }
      chmax(ret, func(v));
    }
    REP(i, n) {
      vector<char> v;
      int y = i, x = 0;
      while(IN(0,n,x) && IN(0,n,y)) {
        v.push_back(s[y][x]);
        y++, x++;
      }
      chmax(ret, func(v));
    }
    cout << ret << endl;
  }

  return 0;
}

