Step 1: Set 1 and 2 first.
Step 2: Set the number 3.
By moving the letters, arrange 123 in an inverted "L" shape, then let 1 make a hole like swallowing a snake, let the third row be in the middle of the first row, let the third row make a hole, then get to the right place, and finally follow 2, 1.
The third and most important step is to find a group of good friends 4.7, connect 4 and 7 together and arrange them in the designated seats. The remaining numbers can tell the space to simply move. It should be noted that if the numbers 4 and 7 are in the third row, they should be sorted in the order of 47. If the numbers 4 and 7 are in the second row, they should be sorted in the order of 74, and then the numbers can be moved.