There are more than a dozen departments, with about 80 people in one department, and there are only about five or six people in each department. More than a dozen departments can be grouped according to ABCD. A group represents a department, and the same group will be avoided during the draw. That is to draw a person from department A, and his opponent will play against a person from department B (department B is also drawn by lot). Try not to let all departments of A play against department B, and A against C, D, E, etc.

The winner of the second round of knockout rounds will be drawn again, which will prevent employees from the same department from meeting in advance.