The title is as follows: Someone chooses a card from a hand.

Mr. Y knows the number of points, but he says he doesn't know this card, which means that the number of points in this card is repeated, that is, this card can't be between J, 8, 2 and K, but only

Spades 4

Red heart AQ4

A5 building

Cao Hua Q54

Mr. X said that I know you don't know this card, which means that it must be because he can't get a few colors, only corresponding to a unique color, such as spades J, 8, 2; Cao Hua K.

So there are only two colors left: heart and diamond.

Red heart AQ4

A5 building

If it is A, then Mr. Y is not sure about this card, but he says he knows this card, so it can only be Q4 of hearts; Box 5. If it is a suit of hearts, then Mr. X is not sure, but he also knows, so this card can only be Box 5.

It's a little complicated. Don't hit me with bricks!