What is a tortoise array?

Swing: 4 cards are placed horizontally and 4 cards are placed vertically on the back of poker. Then put a card at the intersection of every four cards until there is only one intersection, and put a face-up poker at this intersection. The tortoise's body came out.

Then use the remaining poker to put six "claws" on the edge of the body in eight directions, and put three cards on each "claw". So there will be no cards in your hand after the game.

How to play: Just find a pair and put it in your hand to continue the flop. Until the "tortoise array" is fully opened. It is said that Chiang Kai-shek has never solved it.