That means that after creating nodes for yourself, your siblings, your children, and your parents, add your four grandparents next, and then their eight parents, and so on.
When building the leaves of your family tree, prioritize going directly up the family tree. That means that after creating nodes for yourself, your siblings, your children, and your parents, add your four grandparents next, and then their eight parents, and so on. You will quickly find that you have hit a dead end. Do not despair! This is just the beginning.