How is the life palace degree 18 calculated?

In Ziping's eight-character fortune-telling, there is a life palace, which corresponds to 12 God respectively, and can manage the good and bad of a person's life (12 God is also used in a small period, but only for one month).

The algorithm for calculating the life palace is as follows: firstly, determine the degrees of the earthly branches (degrees are: Yin 1, Mao 2, Chen 3, Si 4, Wu 5, Wei 6, Shen 7, You 8, Xu 9, Hai 10, Zi 165438, Ugly 65438). How many degrees, that is, He Gong imperial system. After calculating the land, you can push the moon fortune-telling palace from the date of birth.