Thanks bupaje,

Bupaje sent me PM about James has another good idea.

First, I have placed all my trees at my level . After testing i have wrote this script.

James' s idea is not to place all trees to level. It is a BIG job. We can create just TREE_MAP picture that has tree positions. Another Good Idea ! It will save time.

The Empire of the Mongols comprised the largest continuous land empire ever, reaching from Korea to Poland