def count(line)
  line.chunk {|i| i.nonzero?}.select(&:first).map {|l| l.last.size}.max || 0
end

until (n = $<.gets.to_i).zero?
  field = n.times.map {$<.gets.chomp.chars.map(&:to_i)}
  
  max_l = field.map {|l| count(l)}.max
  max_l = [field.transpose.map {|l| count(l)}.max, max_l].max
  l = n - 1
  n.times do |i|
    line = (i + 1).times.map {|j| field[i - j][j]}
    tmp1 = count(line)
    line = (i + 1).times.map {|j| field[l - i + j][l - j]}
    tmp2 = count(line)
    line = (i + 1).times.map {|j| field[i - j][l - j]}
    tmp3 = count(line)
    line = (i + 1).times.map {|j| field[l - i + j][j]}
    tmp4 = count(line)
    max_l = [tmp1, tmp2, tmp3, tmp4, max_l].max
  end
  
  puts max_l
end
