class Yukicoder
  attr_accessor :matrix

  NONE = 0
  WIN = 1
  LOSE = 2

  def initialize
    @n = gets.to_i
    @matrix = Array.new(@n){ Array.new(@n, -1) }
    @answer = Float::INFINITY

    @n.times do |i|
      s = gets.chomp

      s.chars.each_with_index do |ch, j|
        case ch
        when '-'
          matrix[i][j] = NONE
        when 'o'
          matrix[i][j] = WIN
        when 'x'
          matrix[i][j] = LOSE
        end
      end
    end

    dfs(0, 0)

    puts @answer
  end

  def dfs(i, j)
    if @n-1 == i && @n-1 == j
      check
    else
      if matrix[i][j] == NONE
        matrix[i][j] = WIN
        matrix[j][i] = LOSE
        if j == @n-1
          dfs(i+1, 0)
        else
          dfs(i, j+1)
        end

        matrix[i][j] = LOSE
        matrix[j][i] = WIN
        if j == @n-1
          dfs(i+1, 0)
        else
          dfs(i, j+1)
        end

        matrix[i][j] = NONE
        matrix[j][i] = NONE
      else
        if j == @n-1
          dfs(i+1, 0)
        else
          dfs(i, j+1)
        end
      end
    end
  end

  def check
    win_count = matrix[0].count(WIN)

    rank = 1 + matrix[1..-1].map{|list|
      list.count(WIN) || 0
    }.select{|n| n > win_count}.uniq.size

    @answer = [@answer, rank].min
  end
end

Yukicoder.new