2-3 2-4 2-5 2-6 2-7 2-8 2-9
3-4 3-5 3-6 3-7 3-8 3-9
4-5 4-6 4-7 4-8 4-9
5-6 5-7 5-8 5-9
6-7 6-8 6-9
7-8 7-9
8-9
(8+ 1)*8/2=36 (field)
If there are nine students playing badminton in class 62 now, if two students play one game, one * * * will be more than 36 games.