How to group the class 13 river race?

Divide into 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 * * 10, draw lots, 1, 2, 3, 4, and so on, and then decide the winners of the five groups. Then draw lots with 1, 2, 3, 4, 5, 1 and 2, 3 and 4, 5 to win the prize directly. In the end, there are only three groups left, 1 and 2, 2 and 3, 1 and 3, and finally the two groups with the most wins are selected for the final. If only 1 wins, the other two groups are 1 wins and 1 loses, and the group that wins the most wins directly. I copied it from someone else.