How to group the 27-a-side badminton competition?

In the 27-person competition, if one person is drawn in the first round, you can directly enter the next round.

The remaining 26 people are divided into 13 groups, and two people play the knockout round. The winner of 13, together with one person in the first round, continues to the knockout stage. After the elimination, the seven winners can compete in the single round robin system, or they can compete in the next round of single round robin system after one person continues to have a bye.