Let me give the landlord a detailed explanation and explanation. Ah, under the normal circumstances of a harmonious society, three couples and six talents are acceptable to us, but in real life, this is often not the case. There are often men and women who don't put their feelings into watching horses while riding donkeys, carrying girlfriends and boyfriends and other girls and boys ... The solution to the following problem is that one man and one woman can only form a pair, and three people (two men and one woman and one man) can only form two pairs at most, two men and four women can form at least two pairs, or three pairs can form four pairs at most, without repetition, so three pairs can have at least three people and at most six people. You got it?