json.shixun_lists @subject.stages.each do |stage|
  json.array! stage.stage_shixuns do |stage_shixun|
      shixun = stage_shixun.shixun
      json.number "#{stage.position}-#{stage_shixun.position}"
      json.shixun_name shixun.name
      json.member_count shixun.myshixuns_count
      json.school_count UserExtension.where(user_id: shixun.myshixuns.pluck(:user_id)).pluck(:school_id).uniq.length
    end
end