#include <iostream>
#include <string>
using namespace std;
int board[255][255],dx[] = {1,-1,0,1},dy[] = {0,1,1,1};
int main(){
	int n,tx,ty,cnt,max;
	string str;
	while(cin >> n,n){
		max = 0;
		for(int i = 0;i < n;++i){
			cin >> str;
			for(int j = 0;j < str.size();++j){
				board[i][j] = (int)(str[j] - '0');
			}
		}
		for(int i = 0;i < n;++i){
			for(int j = 0;j < n;++j){
				if(board[i][j] == 1){
					for(int k = 0;k < 4;++k){
						cnt = 1;
						tx = j + dx[k];
						ty = i + dy[k];
						while(0 <= tx && 0 <= ty && tx < n && ty < n && board[ty][tx] == 1){
							++cnt;
							tx += dx[k];
							ty += dy[k];
						}
						if(cnt > max) max = cnt;
					}
				}
			}
		}
		cout << max << endl;
	}
	return 0;
}