What do you think of Jiugong gossip?

4 ? 9 ? 2

3 ? 5 ? seven

8 ? 1 ? six

This picture adds up to 15.

One person wears nine shoes, three shoes on the left, seven shoes on the right, two shoes on four shoulders and six shoes on eight shoulders.

Nine palaces of mathematics: the sum of the numbers on the vertical and horizontal diagonal lines is fifteen.

That is to say, 123456789 is divided into three lines, the centers of the first and third lines are nine and one, the left and right of the middle line are seven and three, the left and right of the first line are two and four, and the left and right of the third line are six and eight. Five is in the middle.