ab ac ad ae af ag ah ai aj

bc bd be bf bg bh bi bj

cd ce cf cg ch ci cj

De df dg dh di dj

ef eg eh ei ej

Fiber, fiber, fiber.

gh gi gj

Hi hj

In the neck

If there are 405 people, in theory, there can be 9 people to choose from in each situation. There is no guarantee that no less than 65,438+00 voters will vote for the same two candidates. If there are 406 people, it can be guaranteed.