Grouping: Eight classes are divided into group A and group B. Each class in the group plays 3 games (each class in the same group plays). The point system is: win 1 game, with 2 points. Negative 1 min. Abstain 0 points. Take the top two in each group and enter the knockout stage! (If the integrals are the same. Team 2 can play overtime.
Elimination: There are 4 teams in Group A and Group B, which can be A 1-B2 and B 1-A2. Play, 1 elimination. Until the final, those who didn't make it to the final will have another game. Divide into three or four parts.
There are four teams in Group A and Group B, which can be A3-B3 and B4-A4. Play, 1 elimination. Decide five, six, seven and eight.