N = gets.to_i
M = 31
S = N.times.map{
  gets[0,N]
}
mask = 0
last_mask = 0
S.each_with_index{|s, y|
  s.chars.each_with_index{|c, x|
    next if y >= x
    n = y * N + x
    last_mask |= 1 << 1 * n
    next if c == ?-
    # 試合済み
    mask |= 1 << 1 * n
    # 勝利
    mask |= 1 << 1 * n + M if c == ?o
  }
}
f = ->mask{
  if (mask & (1 << M) - 1) == last_mask
    table = [0] * N
    N.times{|y|
      N.times{|x|
        next if y >= x
        r = mask & (1 << y * N + x + M) > 0
        table[y] += 1 if r
        table[x] += 1 if !r
      }
    }
    table.uniq.sort_by{|v|-v}.index(table[0]) + 1
  else
    N.times{|y|
      N.times{|x|
        next if y >= x
        n = y * N + x
        # 試合済み
        next if mask & (1 << n) > 0
        lose_mask = mask | (1 << n)
        win_mask = lose_mask | (1 << n + M)
        return [f[lose_mask], f[win_mask]].min
      }
    }
  end
}
p f[mask]