To measure the coming of a dragon, you need to look at it. First of all, you need to know the concepts of Zushan, Shaozushan, parents, and Luantou. To enter the head, you need to stand on the top of the parents' mountain and measure the parents' mountain and the back. In the section of "Lailong", your back is to your parents' mountain, and you are facing Shaozu Mountain. After aligning the north and south, you will know what the word "lailong" is depending on what character you are standing opposite. The details of "lailong" are different from "lailong". It's better to go to the forum to learn. Occasionally, there is a post on the Yi forum to explain it. Take a look.