In the recent table tennis match held by the school, there was a match between every two students, and a total of 28 matches were played. How many students participated in this match?
在学校最近进行的乒乓球比赛中，每两个同学之间都要进行一场比赛，共进行了28场比赛，那么这次比赛一共有多少同学参加．
<result>8</result>